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XIV Latin American Regional IAU Meeting
iii
Contents
XIV Latin American Regional IAU Meeting
Preface
vii
Programme
ix
List of participants
xiii
Review & Invited Talks
Short Talks
Planetary Systems
27
Stars & Stellar Systems
41
Star Formation
85
ISM
95
Galaxies
103
AGN
141
Cosmology
153
High Energy Astrophysics
165
Instrumentation
173
Teaching & Outreach
183
Posters
Planetary Systems
195
Stars & Stellar Systems
235
Star Formation
321
ISM
339
Galaxies
357
AGN
419
Cosmology
447
High Energy Astrophysics
473
Instrumentation
487
Author index
v
Preface
From Santiago (1978), to Mérida (Venezuela, 1981), Buenos Aires (1983), Rio de
Janeiro (1984), Mérida (México, 1986), Gramado (1989), Viña del Mar (1992),
Montevideo (1995), Tonantzintla (1998), Córdoba (2001), Pucón (2005), Isla
Margarita (2007), and Morélia (2010), Latin American Regional IAU Meetings
(LARIM) have witnessed tremendous advances in astronomy world-wide, and
particularly in Latin America. Throughout its 35-year-long history, LARIMs have
played an important role in bringing together scientists from our countries,
fostering collaborations and interchanges at various levels and different areas.
Following this successful tradition, this 14th LARIM covers topics across the
whole field of astronomy, comprising plenary, parallel and poster sessions dedicated to areas such as planetary systems, stars, stellar systems, star formation,
ISM, galaxies, AGN, cosmology, high energy astrophysics, instrumentation,
history, teaching and outreach.
Scientific Organizing Committee:
Zulema Abraham, IAG/USP, Brasil (chair)
Roberto Cid Fernandes, UFSC, Brasil (chair)
Alejandro Córsico, UNLP, Argentina
Fernando Roig, ON, Brasil
Leopoldo Infante, PUC, Chile
William Lee, IA-UNAM, Mexico
Tabaré Gallardo, Facultad de Ciencias, Uruguay
Cesar Briceño Avila, CIDA, Venezuela
Local Organizing Committee:
Roberto Cid Fernandes, UFSC, Brasil
Jane Gregorio-Hetem, IAG/USP, Brasil
Abı́lio Mateus, UFSC, Brasil
Bernardo Borges, UFSC, Brasil
Daniela Pavani, UFRGS, Brasil
Maria Jaqueline Vasconcelos, UESC, Brasil
Natalia Vale Asari, UFSC, Brasil
Silvia H. P. Alencar, UFMG, Brasil
Sponsors: CAPES, CNPq, FAPEMIG, FAPESC, FAPESP, IAG, IAU, SAB, UFSC.
Cover credits: Eduardo Lacerda; photos by Eduardo Schumacher & ESO/VVV
Survey.
vii
viii
Programme
Final Programme
Sun (24/Nov)
Mon (25/Nov)
Tue (26/Nov)
Wed (27/Nov)
Thu (28/Nov)
Fri (29/Nov)
08:45
Opening
09:00
Review talk
Review talk
Review talk
Review talk
Review talk
09:40
Invited talk
Invited talk
Invited talk
Invited talk
Invited talk
10:10
Coffee &
Posters
Coffee &
Posters
Coffee &
Posters
Coffee &
Posters
Coffee &
Posters
11:00
Parallel
sessions
Parallel
sessions
Parallel
sessions
Parallel
sessions
Parallel
sessions
12:40
Lunch
Lunch
Lunch
Lunch
Lunch
15:00
Invited talk
Invited talk
Invited talk
Invited talk
15:30
Review talk
Review talk
Review talk
Invited talk
16:10
Invited talk
Invited talk
Invited talk
Invited talk
Coffee &
Posters
Coffee &
Posters
Coffee &
Posters
Coffee &
Posters
Parallel
sessions
Parallel
sessions
Parallel
sessions
Parallel
sessions
LARIM
Assembly
SAB
Assembly
16:40
Registration
17:30
Free
19:10
20:00
Cocktail
Conference
Dinner
Detailed program
Parallel sessions are divided into the following areas: Planetary Systems (PS), Star formation (SF), Interstellar
Medium (ISM), Galaxies (GAL), Active Galactic Nuclei (AGN),
ix Stars & Stellar Systems (SSS), Vista Variables in the
Via Lactea (VVV), Cosmology (COS), High Energy Astrophysics (HEAP), Instrumentation (INST), Teaching &
Outreach (TO). For details click on individual links.
Outreach (TO). For details click on individual links.
Mon (25/Nov)
08:459:00
Tue (26/Nov)
Wed (27/Nov)
Thu (28/Nov)
Fri (29/Nov)
Opening
Solar
Transient
Activity:
Magnetic
Energy
Release and
Topology
C. Mandrini
(IAFE,
Argentina)
White Dwarf
Stars
S. O. Kepler
(UFRGS,
Brazil)
Galaxies at
High Redshift
F. Bauer
(PUC, Chile)
Testing
Fundamental
Hypotheses in
Cosmology
J. Alcaniz
(ON, Brazil)
09:4010:10
Impact studies
in Latin
America
G. Tancredi
(IFFC, Uruguay)
The SNC
Meteorites
M. E. Varela
(ICATE,
Argentina)
The evolution
of
protoplanetary
disk
M. Schreiber
(UV, Chile)
The star
formation
history of
galaxies in the
CALIFA survey
R. GonzálezDelgado
(IAA, Spain)
Multiple-tracer
surveys of the
large-scale
structure of
the Universe
R. Abramo
(USP, Brazil)
10:1011:00
Coffee &
Posters
Sessions
GAL-1
SSS-1
PS-1
SF-1
Coffee &
Posters
Sessions
GAL-2
SSS-3
PS-2
SF-2
Coffee &
Posters
Sessions
GAL-3
SSS-5
PS-3
COS-1
Coffee &
Posters
Sessions
GAL-4
SSS-6
HEAP-1
COS-2
Coffee &
Posters
Sessions
GAL-6
SSS-8
HEAP-2
COS-3
11:0012:40
Short talks
Parallel
Sessions
GAL-1
SSS-1
PS-1
SF-1
Short talks
Parallel
Sessions
GAL-2
SSS-3
PS-2
SF-2
Short talks
Parallel
Sessions
GAL-3
SSS-5
PS-3
COS-1
Short talks
Parallel
Sessions
GAL-4
SSS-6
HEAP-1
COS-2
Short talks
Parallel
Sessions
GAL-6
SSS-7
HEAP-2
COS-3
12:4015:00
Lunch
Lunch
Lunch
Lunch
Lunch
A New Chinese
Astronomy
New
Opportunities
with the
09:0009:40
Distribution
and Origin of
Hot Planets
C. Beauge
(OAC,
Argentina)
ESO: Present
x
Outreach (TO). For details click on individual links.
Mon (25/Nov)
08:459:00
15:0015:30
09:0009:40
15:3016:10
09:4010:10
10:1016:1011:00
16:40
11:0012:40
16:4017:30
12:4015:00
17:3019:10
15:0015:30
A New Chinese
Opening
Astronomy
Center in Chile
Z. Wang
(CASSACA,
Chile)
Distribution
and Origin of
Hot Planets
C. Beauge
(OAC,
Argentina)
Supergiants,
Stellar Winds
and Mass-loss
L. Cidale
Impact
(UNLP, studies
in
Latin
Argentina)
America
G. Tancredi
(IFFC, Uruguay)
Tue (26/Nov)
New
Opportunities
with the
Gemini
Observatory
Solar
M. Boccas
Transient
(Gemini
Activity:
Observatory,
Magnetic
USA)
Energy
Release and
Topology
C. Mandrini
(IAFE,
Argentina)
Active Galactic
Nuclei
P. Arévalo
The
SNC
(PUC,
Chile)
Meteorites
M. E. Varela
(ICATE,
Argentina)
Abundance
determinations
Coffee
&
in ionized
Posters
nebulae and
Sessions
their
GAL-1
sensitivity to
SSS-1
temperature
PS-1
M. Rodríguez
SF-1
(INAOE,
Mexico)
Short talks
Parallel
Coffee &
Sessions
Posters
GAL-1
Sessions
SSS-1
SSS-2
PS-1
AGN-1
SF-1
ISM-1
INST-1
Diversity of
protoplanetary
Coffee
&
disks in stellar
Posters
clusters: the
Sessions
case of the
GAL-2
sigma Orionis
SSS-3
cluster
PS-2
J. Hernández
SF-2
(CIDA,
Venezuela)
Short talks
Parallel
Coffee &
Sessions
Posters
GAL-2
Sessions
SSS-3
SSS-4
PS-2
AGN-2
SF-2
ISM-2
INST-2
Lunch
Lunch
Short talks
Parallel
Sessions
SSS-2
A
New Chinese
AGN-1
Astronomy
ISM-1 in Chile
Center
INST-1
Z.
Wang
(CASSACA,
Chile)
Short talks
Parallel
New
Sessions
Opportunities
SSS-4
with
the
AGN-2
Gemini
ISM-2
Observatory
INST-2
M. Boccas
(Gemini
Observatory,
USA)
Wed (27/Nov)
White Dwarf
Stars
S. O. Kepler
(UFRGS,
Brazil)
The evolution
of
protoplanetary
disk
M. Schreiber
(UV, Chile)
Free
Coffee &
Posters
Sessions
GAL-3
SSS-5
PS-3
COS-1
Short talks
Parallel
Sessions
GAL-3
SSS-5
PS-3
COS-1
Lunch
xi
Thu (28/Nov)
Fri (29/Nov)
ESO: Present
and Future
A. Kaufer
(ESO, Chile)
Mmtron
T. de Graauw
(ALMA, Chile)
Galaxies at
High Redshift
F. Bauer
(PUC, Chile)
Testing
Fundamental
Hypotheses in
Cosmology
J. Alcaniz
The
SOFIA
(ON, Brazil)
Airborne
Galactic
Dynamics:
Origin,
History,
The starand
Present
formation
Prospect
history
of
B.
Pichardo
galaxies
(UNAM, in the
CALIFA survey
Mexico)
R. GonzálezDelgado
(IAA, Spain)
Determining
Coffee
&
the
distances
Posters
of the
Sessions
structures
GAL-4
surrounding
SSS-6
super-massive
HEAP-1
black
holes
COS-2
K.
Steenbrugge
(UCN, Chile)
Short talks
Parallel
Coffee
&
Sessions
Posters
GAL-4
Sessions
SSS-6
SSS-7
HEAP-1
GAL-5
COS-2
AGN-3
TO-1
Infrared
Observatory first science
highlights and
Multiple-tracer
future
science
surveys of the
potential
large-scale
H.
Zinnecker
structure of
(SOFIA
the Universe
Science
Center,
R. Abramo
NASA,
USA)
(USP, Brazil)
Star and
planet
Coffee &
formation
Posters in
the
era of the
Sessions
submillimeter
GAL-6
observatories
SSS-8
SMA/ALMA
HEAP-2
L.
Zapata
COS-3
(UNAM,
Mexico)
Short talks
Parallel
Sessions
Coffee
&
GAL-6
Posters
SSS-7
Sessions
HEAP-2
SSS-9
COS-3
GAL-7
TO-2
Lunch
Lunch
Short talks
Parallel
Sessions
VVV-1
GAL-5
ESO: Present
AGN-3
and Future
TO-1
A. Kaufer
(ESO, Chile)
Short talks
Parallel
Sessions
SSS-8
GAL-7
Mmtron
VVV-2
T. de Graauw
TO-2
(ALMA, Chile)
xii
List of participants
Mario Gabriel ABADI, Observatorio Astronómico-IATE, Universidad Nacional de Cordoba-CONICET, Argentina
[email protected]
Zulema ABRAHAM, IAG/USP, Brazil
[email protected]
Luis Raul ABRAMO, Instituto de Fı́sica, Universidade de São Paulo, Brazil
[email protected]
Ximena Celeste ABREVAYA, IAG - Universidade de Sao Paulo, Brazil
[email protected]
Gustavo Adolfo AGUAYO, Universidad de Concepcion, Chile
[email protected]
Michel AGUENA DA SILVA, Universidade de São Paulo - Instituto de Fı́sica, Brazil
[email protected]
Paula AGUIRRE, Universidad Andrés Bello, Chile, Chile
[email protected]
Carolina Belen AGURTO GANGAS, Universidad de Valparaiso, Chile
[email protected]
Lara ALBANESE, INAF, OSSERVATORIO DI ARCETRI, Italy
[email protected]
Jailson ALCANIZ, Observatório Nacional , Brazil
[email protected]
Silvia Helena Paixão ALENCAR, Dep. de Fisica - ICEx - UFMG, Brazil
[email protected]
Silvia Teixeira ALEXANDRE, Federal University of Rio de Janeiro, Brazil
[email protected]
Leonardo Andrade ALMEIDA, Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas - IAG/USP, Brazil
[email protected]
Pedro Viana ALMEIDA, Universidade Federal de Minas Gerais, Portugal
[email protected]
Javier ALONSO-GARCÍA, Pontificia Universidad Católica de Chile, Chile
[email protected]
xiii
Alvaro ALVAREZ-CANDAL, Observatório Nacional, Brazil
[email protected]
Virgı́nia Mello ALVES, Universidade Federal de Pelotas (UFPel), Brazil
[email protected]
Eliana Maritza AMAZO-GOMEZ, Universidad Nacional de Colombia, Colombia
[email protected]
Alexandre AMORIM, Núcleo de Estudo e Observação Astronômica ”José Brazilı́cio de Souza”, Brazil
[email protected]
Inaiara Saraceni de ANDRADE, Universidade de São Paulo, Brazil
[email protected]
Ileana ANDRUCHOW, Instituto de Astrofı́sica de La Plata - IALP/CONICET, Facultad de Ciencias Astronómicas y Geofı́sicas
- FCAGLP/UNLP, Argentina
[email protected]
Mateus de Souza ANGELO, Universidade Federal de Minas Gerais, Brazil
[email protected]
Rodolfo ANGELONI, Departamento de Astronomı́a y Astrofı́sica - Pontificia Universidad Católica de Chile, Chile
[email protected]
Ignacio ARAYA, Universidad de Valparaı́so, Chile
[email protected]
Santiago ARCEO-DIAZ, Universidad de Guanajuato, Mexico., Mexico
[email protected]
Catalina Alejandra ARCOS, Universidad de Valparaı́so, Chile
[email protected]
Patricia AREVALO, Universida Andrés Bello & Pontificia Universidad Católica, Chile
[email protected]
Julia Ines ARIAS, Universidad de La Serena, Chile
[email protected]
Cristóbal ARMAZA, Pontifica Universidad Católica de Chile, Chile
[email protected]
Edmundo Marcelo ARNAL, Instituto Argentino de Radioastronomia (IAR), CONICET, CCT-La PLata y Facultad de
Ciencias Astronómicas y Geofı́sicas (FCAG), Universidad Nacional de La Plata, Argentina
[email protected]
Maria Celeste ARTALE, Instituto de Astronomı́a y Fı́sica del Espacio (IAFE), Argentina
[email protected]
Hernán ASOREY, GIRG, Escuela de Fı́sica, Universidad Industrial de Santander, Colombia
[email protected]
Anelise AUDIBERT, Universidade Federal do Rio Grande do Sul, Brazil
[email protected]
Vladimir AVILA-REESE, Instituto de Astronomı́a, UNAM, Mexico
[email protected]
Luiz Mauricio AZANHA, Universidade de São Paulo, Brazil
[email protected]
xiv
Eduardo BALBINOT, Universidade Federal do Rio Grande do Sul, Brazil
[email protected]
Raymundo BAPTISTA, Universidade Federal de Santa Catarina (UFSC), Brazil
[email protected]
Laura Daniela BARAVALLE, Facultad de Matemática, Astronomı́a y Fı́sica. Universidad Nacional de Córdoba, Argentina
[email protected]
Rodolfo H. BARBA, Universidad de La Serena, Chile
[email protected]
Ulisses BARRES DE ALMEIDA, Centro Brasileiro de Pesquisas Fisicas (CBPF/MCTI), Brazil
[email protected]
Caio BARROS SIMÕES DE ALMEIDA, Universidade Federal do ABC (UFABC), Brazil
[email protected]
Franz Erik BAUER, Pontificia Universidad Católica de Chile, Chile
[email protected]
Juan Carlos BEAMÍN, Pontificia Universidad Católica de Chile, Chile
[email protected]
Cristian BEAUGE, Observatorio Astronomico, Universidad Nacional de Cordoba, Argentina
[email protected]
Dino BEGHETTO JUNIOR, UNIVAP - Universidade do Vale do Paraı́ba, Brazil
[email protected]
Diogo BELLONI, Universidade Federal do Rio de Janeiro, Brazil
[email protected]
Rodrigo BERNADELLI, Universidade Federal de Santa Catarina, Brazil
[email protected]
Cristian Giovanny BERNAL, Instituto de Astronomı́a - UNAM, Mexico
[email protected]
Rafael Luiz BERNARDI, Universidade Federal de Santa Catarina, Brazil
[email protected]
Armando BERNUI, Observatório Nacional, MCTI, Brazil
[email protected]
Beatriz BLANCO SIFFERT, Instituto de Fı́sica - Universidade Federal do Rio de Janeiro, Brazil
[email protected]
Maxime BOCCAS, Gemini Observatory, Chile
[email protected]
Bernardo Walmott BORGES, Universidade Federal de Santa Catarina (UFSC) - Campus Araranguá, Brazil
[email protected]
Daniela BORGES PAVANI, Departamento de Astronomia/IF/UFRGS, Brazil
[email protected]
Jura BORISSOVA, Departamento de Fı́sica y Astronomı́a, Facultad de Ciencias, UNIVERSIDAD DE VALPARAÍSO, Chile
[email protected]
xv
Germano BORTOLOTTO, Universidade Federal de Santa Catarina, Brazil
[email protected]
Rodrigo Carlos BOUFLEUR, Observatório Nacional - MCTI, Brazil
[email protected]
Joao BRAGA, INPE, Brazil
[email protected]
Pedro Ivo de Oliveira BRASIL, Instituto Nacional de Pesquisas Espaciais - INPE, Brazil
pedro [email protected]
Paulo Sergio BRETONES, Universidade Federal de São Carlos, Brazil
[email protected]
Eduardo Rondon BRICEÑO, Observatorio nacional , Brazil
[email protected]
Albert BRUCH, Laboratório Nacional de Astrofı́sica, Brazil
[email protected]
Carine BRUM, Universidade Federal De Santa Maria, Brazil
[email protected]
Gustavo BRUZUAL, CRyA, UNAM, Campus Morelia, Mexico
[email protected]
Julio Ignacio BUENO DE CAMARGO, Observatório Nacional / MCTI, Brazil
[email protected]
Filomena BUFANO, Universidad Andres Bello, Chile
[email protected]
Blakesley BURKHART, University of Wisconsin Madison (USA), Universidade Federal do Rio Grande do Norte (Brazil),
United States
[email protected]
Claudio CACERES, Universidad de Valparaiso, Chile
[email protected]
Rolando CALDERÓN ARDILA, Universidad Industrial de Santander, Colombia
[email protected]
Diego Nicolás CALDERÓN ESPINOZA, Pontificia Universidad Católica de Chile, Chile
[email protected]
Marcos Rogerio CALIL, Planetário e Teatro Digital de Santo André - Johannes Kepler, Brazil
[email protected]
Nelson CALLEGARI JR., UNESP, Brazil
[email protected]
Hugo Orlando CAMACHO CHAVEZ, Departamento de Fı́sica Matemática. Instituto de Fı́sica. Universidade de São
Paulo, Brazil
[email protected]
Jose Iván CAMPOS-ROZO, Universidad Nacional de Colombia, Colombia
[email protected]
Luis E. CAMPUSANO, Departamento de Astronomia, Universidad de Chile, Chile
[email protected]
xvi
Graeme Nicholas CANDLISH, Universidad de Concepción, Chile
[email protected]
Hector CANOVAS, Departamento de Fisica y Astronomı́a, Universidad de Valparaı́so, Valparaı́so, Chile, Chile
[email protected]
Elenna CAPOTE, Massachusetts Institute of Technology, Pontifica Universidad Catolica de Chile, United States
[email protected]
Cristina Elisabet CAPPA, Instituto Argentino de Radioastronomı́a, CONICET, Argentina, y Facultad de Ciencias Astronómicas y Geofı́sicas, UNLP, Argentina , Argentina
[email protected]
Anderson CAPRONI, Universidade Cruzeiro do Sul, Brazil
[email protected]
Julio A. CARBALLO-BELLO, Universidad de Chile, Chile
[email protected]
Alex C. CARCIOFI, IAG/USP, Brazil
[email protected]
Adair CARDOSO, Universidade Federal de Santa Catarina, Brazil
[email protected]
Marı́lia Gabriela CARDOSO CORRÊA CARLOS, Instituto Nacional de Pesquisas Espaciais, Brazil
[email protected]
César Augusto CARETTA, Universidad de Guanajuato (Departamento de Astronomı́a), Mexico, Mexico
[email protected]
Carolina Moura CARNEIRO, Observatório do Valongo - Universidade Federal do Rio de Janeiro, Brazil
[email protected]
Eleazar Rodrigo CARRASCO, Gemini Observatory, Southern Operations Center, Chile
[email protected]
Maiara Sampaio CARVALHO, Laboratorio de Astrofisica Teorica e Observacional, Universidade Estadual de Santa
Cruz, Brazil
[email protected]
Jorge M. CARVANO, Observatório Nacional , Brazil
[email protected]
Rigoberto CASAS MIRANDA, Universidad Nacional de Colombia, Colombia
[email protected]
Hector O. CASTAÑEDA, Escuela Superior de Fisica y Matematicas - Instituto Politécnico Nacional, Mexico
[email protected]
Camile Mendes CASTILHO, Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, Universidade de São Paulo,
Brazil
[email protected]
Márcio CATELAN, Pontificia Universidad Católica de Chile, Chile
[email protected]
João Paulo Nogueira CAVALCANTE, Observatório do Valongo - Universidade Federal do Rio de Janeiro, Brazil
[email protected]
xvii
Oscar CAVICHIA, Universidade de São Paulo, Brazil
[email protected]
José R. CECATTO, DAS-INPE, Brazil
[email protected]
Jan CECHURA, Astronomical Institute, Academy of Sciences of the Czech Republic, Faculty of Mathematics and Physics,
Charles University in Prague, Czech Republic
[email protected]
César Alexander CHACÓN-CARDONA, Universidad Nacional de Colombia, Colombia
[email protected]
Julio CHANAMÉ, Pontificia Universidad Católica de Chile, Chile
[email protected]
Germán CHAPARRO, Kapteyn Astronomical Institute (previous), Universidad Sergio Arboleda (current), Colombia
[email protected]
Ana CHIES-SANTOS, University of Nottingham, UK, United Kingdom
Ana.Chies [email protected]
Marcel CHOW MARTINEZ, Universidad de Guanajuato, Mexico
[email protected]
Nathália CIBIRKA, Universidade de São Paulo, Brazil
[email protected]
Silvina CICHOWOLSKI, Instituto de Astronomı́a y Fı́sica del Espacio, Argentina
[email protected]
Roberto CID FERNANDES, Universidade Federal de Santa Catarina, Brazil
[email protected]
Lydia Sonia CIDALE, Universidad de La Plata, Argentina
[email protected]
Alejandro CLOCCHIATTI, Pontificia Universidad Catolica de Chile, Chile
[email protected]
Bruno COELHO, Observatório do Valongo/UFRJ, Brazil
[email protected]
Paula R. T. COELHO, Universidade Cruzeiro do Sul, Brazil
[email protected]
Valeria COENDA, IATE - Observatorio Astronómico de Córdoba, Argentina
[email protected]
Roger COHEN, Universidad de Concepcion, Chile
[email protected]
Georgina COLDWELL, ICATE - CONICET, FCEFyN - Universidad Nacional de San Juan, Argentina
[email protected]
Cesar Augusto Huanca CONDORI, Observatório Nacional, Brazil
[email protected]
Sergio Antonio CONTRERAS, Pontificia Universidad Católica de Chile, Chile
[email protected]
xviii
Rodrigo CONTRERAS RAMOS, Universidad Catolica de Chile, Chile
[email protected]
Fernando CORTÉS-SERRANO, Escuela de Fı́sica, Universidad Industrial de Santander, Colombia
[email protected]
Arianna CORTESI, Nottingham University, United Kingdom
[email protected]
Mariela Alejandra CORTI, FCAG(UNLP) - IAR(CONICET), Argentina
[email protected]
Marcus Vinı́cius COSTA DUARTE, Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas - Universidade de São
Paulo, Brazil
[email protected]
Guilherme COUTO, IF-UFRGS, Brazil
[email protected]
Alicia CRUZADO, Facultad de Ciencias Astronómicas y Geofı́sicas, Universidad Nacional de La Plata, Argentina
[email protected]
Jorge CUADRA, P. Universidad Católica de Chile, Chile
[email protected]
Pablo Andrés CUARTAS-RESTREPO, Universidad de Antioquia, Colombia
[email protected]
Héctor CUEVAS, Universidad de La Serena, Chile
[email protected]
Katia CUNHA, Observatorio Nacional - MCTI, Brazil
[email protected]
Michel CURÉ, Departamento de Fisica y Astronomia, Facultad de Ciencias, Universidad de Valparaiso, Chile
[email protected]
Flavio D’AMICO, Instituto Nacional de Pesquisas Espaciais - INPE, Brazil
[email protected]
Clayton Garcia DA SILVA, Universidade de São Paulo, Brazil
[email protected]
Luidhy Santana DA SILVA, Universidade Estadual do Ceará, Brazil
[email protected]
Giannina DALLE MESE, Instituto Nacional de Astrofisica, Optica y Electronica, Mexico
[email protected]
Natacha Zanon DAMETTO, Universidade Federal do Rio Grande do Sul, Brazil
[email protected]
Jorge Gonzales DAVALOS, Observatorio Nacional, Brazil
[email protected]
André Luiz DE AMORIM, Universidade Federal de Santa Catarina, Brazil
[email protected]
Marcio Guilherme Bronzato DE AVELLAR, Universidade de São Paulo (IAG), Brazil
[email protected]
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Marı́a Silvina DE BIASI, Instituo de Astrofı́sica de La Plata (CCT-La PLata CONICET) y Facultad de Ciencias Astronómicas
y Geofı́sicas, Universidad Nacional de La Plata, Argentina , Argentina
mariasilvina [email protected]
Elisabete M. DE GOUVEIA DAL PINO, Universidade de Sao Paulo, Brazil
[email protected]
Thijs DE GRAAUW, ESO, Chile
[email protected]
Jose Ignacio Garcia DE LA ROSA, Observatorio do Valongo, Brazil
[email protected]
Luiz Alberto DE PAULA, Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas da Universidade de São Paulo,
Brazil
[email protected]
Mario Nascimento DE PRA, Observatório Nacional, Brazil
[email protected]
Cleiton Carillo DE SOUZA, Universidade Estadual de Santa Cruz, Brazil
[email protected]
João Eduardo DE SOUZA DA FONSECA, Universidade Estadual Paulista - UNESP, Brazil
[email protected]
Istvan DEKANY, Instituto de Astrofisica, Pontificia Universidad Catolica de Chile, Chile
[email protected]
Maria Victoria DEL VALLE, Instituto Argentino de Radioastronomia IAR, Argentina
[email protected]
Gloria DELGADO INGLADA , Instituto de Astronomı́a, Universidad Nacional Autónoma de México , Mexico
[email protected]
Josselin DESMARS, Observatorio Nacional de Rio de Janeiro, Brazil
[email protected]
Bruno DIAS, IAG/Universidade de São Paulo, Brazil
[email protected]
Rafael Augusto Garcia DIAS, Universidade Federal do Rio Grande do Sul, Brazil
[email protected]
Wilton S. DIAS, Universidade Federal de Itajuba, Brazil
[email protected]
Alex DIAS DE OLIVEIRA, Observatório Nacional, Brazil
[email protected]
Marlon R. DINIZ, Universidade Federal de Santa Maria, Brazil
[email protected]
Suzi Izaquiel Ferreira DINIZ, Universidade Federal do Rio Grande do Sul, Brazil
[email protected]
Isadora Bicalho DOMINGOS, Observatório Nacional, Brazil
[email protected]
Josué Cardoso DOS SANTOS, Universidade Estadual Paulista-UNESP (São Paulo State University), Brazil
[email protected]
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Hélio DOTTO PEROTTONI, Universidade Federal do Rio de Janeiro, Brazil
[email protected]
Horacio Alberto DOTTORI, Universidade Federal do Rio Grande do Sul, Brazil
[email protected]
Daniel Alf DREHMER, Instituto de Fı́sica - Universidade Federal do Rio Grande do Sul, Brazil
[email protected]
João Pedro Wojcikiewicz DUARTE SILVA, Universidade Federal de Santa Catarina, Brazil
[email protected]
Jânia DUHA, Instituto Federal do Paraná, Brazil
[email protected]
Fernanda DUPLANCIC, Instituto de Ciencias Astronómicas, de la Tierra y del Espacio (ICATE), Argentina
[email protected]
Paul EIGENTHALER, Instituto de Astronomı́a y Astrofı́sica, Pontificia Universidad Católica de Chile, Chile
[email protected]
Andres ESCALA, Universidad de Chile, Chile
[email protected]
Cyril ESCOLANO, Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, Brazil
[email protected]
Cesar ESTEBAN, Instituto de Astrofı́sica de Canarias, Spain
[email protected]
Daniel Moser FAES, Instituto de Astronomia, Geofı́sica e Ciências Atmosféicas, Universidade de São Paulo, Brazil
[email protected]
Adriano FAGUNDES, Universidade Federal de Santa Catarina, Brazil
[email protected]
Jacqueline Kelly FAHERTY, Universidad de Chile/Carnegie Institute (DTM), Chile
[email protected]
Nelson FALCON, Universidad de Carabobo, Venezuela
[email protected]
Marcos Antonio Fonseca FARIA, Universidade Federal de Itajubá, Brazil
[email protected]
Jamille Almeida FEITOSA, Universidade Estadual de Santa Cruz, Brazil
[email protected]
Michael FELLHAUER, Departamento de Astronomia, Universidad de Concepcion, Chile, Chile
[email protected]
Oscar Luis FERLE, Universidade Cruzeiro do Sul, Brazil
[email protected]
Mateus César FERNANDES, Universidade Federal do Rio de Janeiro, Brazil
[email protected]
Sylvio FERRAZ MELLO, IAG-USP, Brazil
[email protected]
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Andressa Cristina Silva FERREIRA, Universidade de São Paulo, Brazil
[email protected]
Carlos Eduardo FERREIRA LOPES, Universidade Federal do Rio Grande do Norte, Brazil
carlos [email protected]
Natasha FIORETTO AGUERO, Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas (IAG), Universidade de São
Paulo (USP), Brazil
[email protected]
Verónica FIRPO, Universidad de La Serena, Chile
[email protected]
Matias Gastón FLORES, Instituto de Ciencias Astronómicas, de la Tierra y del Espacio (ICATE) , Argentina
[email protected]
Jaime FORERO-ROMERO, Universidad de los Andes, Colombia
[email protected]
Fabrı́cio Catani FREITAS, Universida de São Paulo, Brazil
[email protected]
Priscila FREITAS-LEMES, Universidade do Vale do Paraı́ba, Brazil
[email protected]
Amancio Cesar Santos FRIACA, IAG-USP, Brazil
[email protected]
Lucas FROZZA SECCO, University of São Paulo, Brazil
[email protected]
Isaura L. FUENTES-CARRERA, Escuela Superior de Fı́sica y Matemáticas, Instituto Politécnico Nacional, Mexico
isaura.fuentes[email protected]
Gaspar GALAZ, Instituto de Astronomia, P. Universidad Catolica de Chile, Chile
[email protected]
Lluis GALBANY, CENTRA - Centro Multidisciplinar de Astrofı́sica, Instituto Superior Técnico, Departamento de Astronomı́a, Universidad de Chile, Chile
[email protected]
Tabare GALLARDO, Instituto de Fisica, Facultad de Ciencias, Universidad de la Republica, Uruguay
[email protected]
Alexandre GALLENNE, Universidad de Concepcion, Chile
[email protected]
Phillip GALLI, Universidade de São Paulo, IAG, Brazil
[email protected]
Diana GAMA, IAG/USP, Brazil
[email protected]
Juan Nicolas GARAVITO, Universidad de los Andes, Colombia
[email protected]
Federico GARCÍA, Instituto Argentino de Radioastronomı́a (IAR-CONICET), Argentina
[email protected]
Miguel Angel GARCIA CALDERON, Universidad Distrital Francisco Jose de Caldas, Colombia
[email protected]
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Alejandro GARCÍA VARELA, Universidad de los Andes, Bogotá, Colombia
[email protected]
Felipe GARRIDO, P. Universidad Católica de Chile, Chile
[email protected]
Hernán Enrique GARRIDO, Universidad de Concepción, and European Southern Observatory, Chile
[email protected]
Claudio GERMANÀ, Departamento de Fı́sica, Universidade Federal do Maranhão, Brazil
[email protected]
Elsa Beatriz GIACANI, Instituto de Astronomı́a y Fı́sica del Espacio, Argentina
[email protected]
Breno Loureiro GIACCHINI, Centro Brasileiro de Pesquisas Fı́sicas, Brazil
[email protected]
Ricardo GIL-HUTTON, Complejo Astronómico El Leoncito - CONICET, Argentina
[email protected]
Rafael Santiago GIROLA, Universidad Nacional de Tres de Febrero, Argentina
[email protected]
Silvia Maria GIULIATTI WINTER, UNESP-Univ. Estadual Paulista, Brazil
[email protected]
Cristian Alberto GOEZ, OLIMPIADAS COLOMBIANAS DE ASTRONOMIA Y ASTROFISICA, Colombia
[email protected]
Rodney S. GOMES, Observatório Nacional, Brazil
[email protected]
Altair Ramos GOMES JUNIOR, Observatório do Valongo - Universidade Federal do Rio de Janeiro, Brazil
[email protected]
Matias GOMEZ, Universidad Andres Bello, Chile
[email protected]
Maria Fernanda GÓMEZ ÁLVAREZ , Universidad de los Andes, Colombia
[email protected]
Denise R. GONÇALVES, Observatório do Valongo - UFRJ, Brazil
[email protected]
Thiago Signorini GONÇALVES, Observatório do Valongo, Universidade Federal do Rio de Janeiro, Brazil
[email protected]
Oscar A. GONZALEZ, European Southern Observatory, Chile
[email protected]
Roberto GONZALEZ, Departamento de Astronomı́a y Astrofı́sica, Pontificia Universidad Catolica, Chile
[email protected]
Rosa Marı́a GONZÁLEZ DELGADO, Instituto de Astrofı́sica de Andalucı́a (CSIC), Spain
[email protected]
Danilo GONZALEZ DIAZ, Universidad Nacional de Colombia, Colombia
[email protected]
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Santiago GONZALEZ GAITAN, Universidad de Chile, Chile
[email protected]
Javier Ernesto GONZÁLEZ SÁNCHEZ , Observatório Nacional, Brazil
[email protected]
Kevin GOVENDER, International Astronomical Union Office of Astronomy for Development, South Africa (zuid Afrika)
[email protected]
Jane GREGORIO-HETEM, Universidade de Sao Paulo - IAG/USP, Brazil
[email protected]
Monica Gladys GROSSO, Instituto de Ciencias Astronómicas de la Tierra y del Espacio, ICATE-CONICET, Argentina
[email protected]
Rafael Fraga GUERÇO, Observatório Nacional - Rio de Janeiro - Brasil, Brazil
[email protected]
Walter Robert GUEVARA DAY, CONIDA - AGENCIA ESPACIAL DEL PERU, Peru
[email protected]
Sebastian GUROVICH, Observatorio Astronomico de Cordoba, Argentina
[email protected]
Claudia Patricia GUTIÉRREZ, Universidad de Chile, Chile
[email protected]
Gergely HAJDU, Pontificia Universidad Católica de Chile, Chile
[email protected]
Margaret M. HANSON, University of Cincinnati, USA, United States
[email protected]
Moiré Gonçalves HENNIG, Universidade Federal de Santa Maria, Brazil
[email protected]
Herman HENSBERGE, Royal Observatory of Belgium, Brazil
[email protected]
Jesus Omar HERNANDEZ, Centro de Investigaciones de Astronomia, Venezuela
[email protected]
Jose Andres HERNANDEZ, Universidade Federal do Rio Grande do Sul, Brazil
[email protected]
Fábio Rafael HERPICH, Universidade Federal de Santa Catarina, Brazil
[email protected]
Annibal HETEM, UFABC - Universidade Federal do ABC, Brazil
[email protected]
Gabriel Rodrigues HICKEL, Universidade Federal de Itajubá, Brazil
[email protected]
Ana Maria HIDALGO-GÁMEZ, Escuela Superior de Fı́sica y Matemáticas, Instituto Politécnico Nacional, Mexico
[email protected]
Mario Armando HIGUERA GARZÓN, Universidad Nacional de Colombia, Colombia
[email protected]
xxiv
Karianne HOLHJEM, Southern Astrophysical Research (SOAR) telescope, Chile, Chile
[email protected]
Mariela HUAMAN ESPINOZA, UNESP - UNIVERSIDADE ESTADUAL PAULISTA ”Júlio de Mesquita Filho”, Brazil
[email protected]
Jiasheng HUANG, Chinese Academy of Sciences South America Center for Astronomy, Chile
[email protected]
Hector Javier IBARRA MEDEL, INAOE, Mexico
[email protected]
Francisco JABLONSKI, Astrophysics Division, INPE/MCTI, Brazil
[email protected]
Yara Lorena JAFFE, Universidad de Concepcion, Chile
[email protected]
Eduardo JANOT PACHECO, USP-IAG, Brazil
[email protected]
Marcelo Daniel JAQUE, ICATE-CONICET/Universidad Nacional de San Juan , Argentina
[email protected]
Vera JATENCO-PEREIRA, Universidade de São Paulo, Brazil
[email protected]
Noelia JIMENEZ, CONICET, University of Trieste, Italy
[email protected]
Emiliano JOFRÉ, Observatorio Astronómico de Córdoba, Argentina
[email protected]
Matias JONES, Universidad de Chile, Chile
[email protected]
Astor João Schönell JÚNIOR, Universidade Federal do Rio Grande do Sul, Brazil
[email protected]
Luı́s Henrique Sinki KADOWAKI, Universidade de São Paulo (IAG/USP), Brazil
[email protected]
Antonio KANAAN, Universidade Federal de Santa Catarina., Brazil
[email protected]
Samer KANAAN, Universidad de Valparaiso , Chile
[email protected]
Andreas KAUFER, European Southern Observatory, Chile
[email protected]
Pierre KAUFMANN, Universidade Presbiteriana Mackenzie, Brazil
[email protected]
S. O. KEPLER, Universidade Federal do Rio Grande do Sul, Brazil
[email protected]
Behrouz KHIALI, University of Sao Paulo- IAG/USP, Brazil
[email protected]
xxv
Jessica Reis KITAMURA, Universidade Cruzeiro do Sul, Brazil
[email protected]
Radostin Georgiev KURTEV, Universidad de Valparaiso, Chile
[email protected]
Eduardo Alberto Duarte LACERDA, Universidade Federal de Santa Catarina, Brazil
[email protected]
Régis LACHAUME, P. Universidad Catolica de Chile, Chile
[email protected]
Paulo Jakson Assunção LAGO, Universidade de São Paulo, Brazil
[email protected]
Natália Rezende LANDIN, Universidade Federal de Viçosa - campus UFV Florestal, Brazil
[email protected]
Gustavo A. LANFRANCHI, NAT - Universidade Cruzeiro do Sul, SP-Brasil, Brazil
[email protected]
Rodolfo LANGHI, UNESP/Bauru - Universidade Estadual Paulista ”Julio de Mesquita Filho”, Brazil
[email protected]
Maritza Arlene LARA-LOPEZ, Australian Astronomical Observatory, Australia
[email protected]
Andres Baquero LARRIVA, Escuela Politecnica Nacional del Ecuador, Ecuador
[email protected]
Daniela LAZZARO, Observatório Nacional, Brazil
[email protected]
Rodrigo Andrés LEIVA ESPINOZA, Instituto de Astrofı́sica, Pontificia Universidad Católica de Chile, Chile
[email protected]
Jacques R. D. LEPINE, Universidade de São Paulo, Brazil
[email protected]
Peter LEROY, PONTIFICIA UNIVERSIDADE CATOLICA DE MINAS GERAIS,MUSEU DE CIENCIAS NATURAIS, Brazil
[email protected]
Orlando Hugo LEVATO, Instituto de Ciencias Astronómicas, de la Tierra y del Espacio (ICATE) , Argentina
[email protected]
Eliade Ferreira LIMA, Universidade Federal do Rio Grande do Sul, Brazil
[email protected]
Gustavo Henrique R. de Araújo LIMA, Departamento de Fı́sica - Universidade Federal de Minas Gerais, Brazil
[email protected]
Marcos LIMA, Universidade de São Paulo, Brazil
[email protected]
Maria Luiza LINHARES DANTAS, Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas da Universidade de São
Paulo, Brazil
[email protected]
Gianluca LOMBARDI, European Southern Observatory, Chile
[email protected]
xxvi
Alexandre Roman LOPES, Universidad de La Serena, Chile
[email protected]
Amanda LOPES, Observatório do Valongo (OV/UFRJ), Brazil
[email protected]
Raimundo LOPES DE OLIVEIRA FILHO, Universidade Federal de Sergipe, Brazil
[email protected]
Sebastian LOPEZ , Universidad de Chile, Chile
[email protected]
Paula Carolina LÓPEZ ESPINOZA, Universidad de Chile, Chile
[email protected]
Rafael LÓPEZ FERNÁNDEZ, Instituto de Astrofı́sica de Andalucı́a - CSIC, Spain
[email protected]
Francisco LÓPEZ-GARCÍA, UNSJ Argentina, Argentina
[email protected]
Zulema LÓPEZ-GARCÍA, ICATE ARGENTINA, Argentina
[email protected]
Diego LORENZO DE OLIVEIRA, Universidade Federal do Rio de Janeiro - Observatório do Valongo, Brazil
[email protected]
Eduardo LOURENCO DE ANDRADE, Universidade Federal de Santa Catarina, Brazil
[email protected]
Gerardo Juan Manuel LUNA, Instituto de Astronomia y Fı̀sica del Espacio (IAFE), Argentina
[email protected]
Elmer Fidel LUQUE, Universidade Estadual de Santa Cruz, Brazil
[email protected]
Josué Antunes de MACÊDO, Instituto Federal de Educação, Ciência e Tecnologia do Norte de Minas Gerais, Brazil
[email protected]
Daniel Iria MACHADO, Unioeste / Foz do Iguaçu, Brazil
[email protected]
Antonio Mario MAGALHAES, IAG - Universidade de Sao Paulo, Brazil
[email protected]
Victor de Souza MAGALHÃES, Currently unaffiliated , Brazil
[email protected]
Marcelo Tucci MAIA, Instituto de Astronomia, Geofı́sca e Ciências Atmosfericas, Universidade de São Paulo., Brazil
[email protected]
Vincenzo MAINIERI, ESO, Germany
[email protected]
Martin MAKLER, Brazilian Center for Physics Research, CBPF/ICRA, Brazil
[email protected]
Stella Maris MALARODA, ICATE-CONICET, Argentina
[email protected]
xxvii
Victoria Eugenia MALDONADO, Instituto de Astronomı́a Teórica y Experimental (IATE), Argentina
[email protected]
Brisa Llaneth MANCILLAS VAQUERA, Universidad Nacional Autónoma de México, Mexico
[email protected]
Cristina H. MANDRINI, Instituto de Astronomı́a y Fı́sica del Espacio, Argentina
[email protected]
Paula MARCHIANO, Facultad de Ciencias Astronómicas y Geofı́sicas, Universidad Nacional de La Plata, Argentina
paula [email protected]
Gabriela Antunes MARQUES, Observatório Nacional, Brazil
[email protected]
Hector Julian MARTINEZ, IATE - Observatorio Astronomico Universidad Nacional de Cordoba, Argentina, Argentina
[email protected]
Sandra M. MARTÍNEZ, Escuela de Fı́sica, Universidad Industrial de Santander, Colombia
[email protected]
Louise Giansante MARTINS, Universidade de São Paulo, Brazil
[email protected]
Lucimara MARTINS, Núcleo de Astrofı́sica Teórica -Universidade Cruzeiro do Sul (NAT-UCS), Brazil
[email protected]
Roberto Vieira MARTINS, Observatório Nacional, Brazil
[email protected]
Silvia Lorenz MARTINS, Universidade Federal do Rio de Janeiro - Observatório do Valongo, Brazil
[email protected]
Walter Silva MARTINS-FILHO, Observatório Nacional, Brazil
[email protected]
Eder MARTIOLI, Laboratorio Nacional de Astrofisica - LNA/MCTI, Brazil
[email protected]
Abı́lio MATEUS, Universidade Federal de Santa Catarina, Brazil
[email protected]
Salomé MATOS, Royal Observatory of Edinburgh, University of Edinburgh, United Kingdom
[email protected]
Maria Fátima MATTIELLO-FRANCISCO, Instituto Nacional de Pesquisas Espaciais (INPE), Brazil
[email protected]
Ana Carolina MATTIUCI, Universidade Estadual do Rio Grande do Norte, Brazil
[email protected]
Francesco MAURO, Universidad de Concepcion, Chile
[email protected]
Daniel MAY, Instituto de Astronomia e Ciências Atmosféricas - USP, Brazil
[email protected]
Natalia Lorena MAZA, Instituto de Ciencias Astronómicas, de la Tierra y del Espacio , Argentina
[email protected]
xxviii
Alfredo Javier MEJÍA, Centro de Investigaciones de Astronomı́a, Venezuela
[email protected]
Brenda Eliana MELENDEZ, Facultad de Ciencias Astronómicas y Geofı́sicas, Universidad Nacional de La Plata (UNLP),
Instituto de Astrofı́sica de la Plata, UNLP-CONICET, Argentina
[email protected]
Claudio MELIOLI, IAG-USP, Brazil
[email protected]
Alexandre Tuoto MELLO, Universidade Federal de Santa Catarina, Brazil
[email protected]
Claudio MELO, ESO/Chile, Chile
[email protected]
Paulo Henrique Guimarães MELQUIADES, Grupo de Astronomia e Astrofı́sica(GAIA). Museu de Ciência Naturais.
Pontifı́cia Universidade Católica de Minas Gerais., Brazil
[email protected]
Luiz Themystokliz Sanctos MENDES, Universidade Federal de Minas Gerais, Brazil
[email protected]
Sandro MENDOZA-CASTREJÓN, Instituto de Astronomı́a, Universidad Nacional Autónoma de México., Mexico
[email protected]
Karin MENENDEZ-DELMESTRE, Valongo Observatory, Federal University of Rio de Janeiro, Brazil
[email protected]
Roberto Bertoldo MENEZES, Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, Universidade de São Paulo ,
Brazil
[email protected]
Adal MESA-DELGADO, Pontificia Universidad Católica de Chile, Chile
[email protected]
Hugo G. MESSIAS, Universidad de Concepcion, Chile
[email protected]
Steffen MIESKE, European Southern Observatory, Chile, Chile
[email protected]
Andre de Castro MILONE, Instituto Nacional de Pesquisas Espaciais (INPE/MCTI), Brazil
[email protected]
Dante MINNITI, Instituto de Astrofisica, Pontificia Universidad Catolica de Chile, Chile
[email protected]
Felix Igor MIRABEL, Instituto de Astronomia y Fisica del Espacio. Conicet-UBA, Argentina
[email protected]
Dayvid de Sousa Miranda Sousa MIRANDA, Universidade Estadual do Rio Grande do Norte, Brazil
[email protected]
Mercedes MOLLA, IAG, Universidade de Sao Paulo and CIEMAT(Madrid, Spain), Brazil
[email protected]
Thiago MONFREDINI, Universidade Federal do Rio de Janeiro, Brazil
[email protected]
xxix
Christian MONI BIDIN, Universidad Catolica del Norte, Chile
[email protected]
Hektor MONTEIRO, Universidade Federal de Itajubá, Brazil
[email protected]
Felipe Antonio MONTEIRO GOMES NOGUEIRA, Observatório do Valongo - Universidade Federal do Rio de Janeiro,
Brazil
[email protected]
Thierry MONTMERLE, Institut d’Astrophysique de Paris, France
[email protected]
Habib Salomon Dumet MONTOYA, CENTRO BRASILEIRO DE PESQUISAS FISICAS, Brazil
[email protected]
Marcelo D. MORA, Instituto de Astrofı́sica, Pontificia Universidad Católica de Chile, Chile
[email protected]
Bruno MORAES, Centro Brasileiro de Pesquisas Fı́sicas, Brazil
[email protected]
Christophe MORISSET, Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Mexico
[email protected]
Juliana Cristina MOTTER, Universidade de São Paulo, Brazil
[email protected]
Décio Cardozo MOURÃO, UNESP - Univ. Estadual Paulista, Brazil
[email protected]
Maximiliano Leonardo MOYANO DANGELO, Universidad Católica del Norte, Chile
[email protected]
Francisco MUELLER-SANCHEZ, UCLA, United States
[email protected]
César Alejandro MUÑOZ, Universidad de Concepción, Concepción, Chile, Chile
[email protected]
Alejandra Marı́a MUÑOZ ARANCIBIA, Pontificia Universidad Católica de Chile, Chile
[email protected]
Juan Carlos MUÑOZ CUARTAS, Instituto de Fisica, Universidad de Antioquia, Colombia
[email protected]
Deisy Lorena MUÑOZ SERNA, Fundación Universitaria Luis Amigó, Colombia
[email protected]
Koraljka MUZIC, European Southern Observatory (ESO), Chile, Chile
[email protected]
Orlando Antonio NARANJO, Universidad de Los Andes. Grupo de Astrofı́sica Teórica. Mérida. Venezuela., Venezuela
[email protected]
John Alexander NARVAEZ, Universidad Nacional de Colombia, Colombia
[email protected]
Raquel Santiago NASCIMENTO, Observatório do Valongo/ Universidade Federal do Rio de Janeiro, Brazil
[email protected]
xxx
Felipe NAVARETE, Universidade de São Paulo, Brazil
[email protected]
Camila NAVARRETE, Pontificia Universidad Catolica de Chile, Chile
[email protected]
Giuliat NAVAS, Centro de Investigaciones de Astronomia ”Francisco José Duarte” (CIDA) , Venezuela
[email protected]
Daniel Marcos NERI-LARIOS, The University of Melbourne, Australia
[email protected]
Oswaldo NIETO, Escuela de Fı́sica, Universidad Industrial de Santander, Colombia
[email protected]
Robert NIKUTTA, Universidad Andres Bello, Chile
[email protected]
Jose Luis NILO CASTELLON, Universidad de La Serena, Chile
[email protected]
Erica Cristina NOGUEIRA, Universidade Federal Fluminense, Observatório Nacional, Brazil
[email protected]
Patricia Martins de NOVAIS, Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas - IAG/USP, Brazil
[email protected]
Rafael da Costa NUNES, Universidade Estudual do Rio Grande do Norte, Brazil
[email protected]
Mónica Alejandra ODDONE, Observatorio Astronómico Córdoba, Universidad Nacional de Córdoba, Argentina
[email protected]
Gabriel Andrés OIO, Instituto de Astronomı́a Teórica y Experimental (IATE), Argentina
[email protected]
Paola Cecilia OLIVA-ALTAMIRANO, Swinburne University of Technology/ Australian Astronomical Observatory (AAO),
Honduras
[email protected]
Felipe OLIVARES E., Physics Department, Universidad Andrés Bello, Chile
[email protected]
Alexandre Soares OLIVEIRA, IP&D-Univap, Brazil
[email protected]
Carolyne Santos OLIVEIRA, Valongo Observatory at the Federal University of Rio de Janeiro, Brazil
[email protected]
Murilo Marinello Assis OLIVEIRA, Universidade Federal de Itajubá., Brazil
[email protected]
Alcides ORTEGA, Dirección de Informática Universidad de Carabobo , Venezuela
[email protected]
René Alberto ORTEGA-MINAKATA, Departamento de Astronomı́a, Universidad de Guanajuato, Mexico, Mexico
[email protected]
Roberto ORTIZ, Universidade de São Paulo, Brazil
[email protected]
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Luis Javier OTINIANO, CONIDA (Comisión Nacional de Investigación y Desarrollo Aeroespacial), Peru
[email protected]
Tania PAEZ TAGLIAFERRO, Universidad Nacional del Córdoba, Argentina
[email protected]
Leonardo Gaston PAIZ, Facultad de Ciencias Astronomicas y Geofisicas - Universidad Nacional de La Plata, Argentina
[email protected]
Tali PALMA, Observatorio Astronómico, Universidad Nacional de Córdoba, Argentina
[email protected]
Miriani Griselda PASTORIZA, Universidade Federal de Rio Grande do Sul, Brazil
[email protected]
Diogo PAULETTI, Universidade Federal de Santa Maria, Brazil
[email protected]
Manuel PEIMBERT, Universidad Nacional Autonoma de Mexico, Instituto de Astronomia, Mexico
[email protected]
Ana PELINSON, UFSC, Brazil
[email protected]
Miriam PEÑA, Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Mexico
[email protected]
Paulo F. PENTEADO, Northern Arizona University, United States
[email protected]
Maria Elidaiana da Silva PEREIRA, Centro Brasileiro de Pesquisas Fı́sicas, Brazil
[email protected]
Margarita PEREYRA, Insituto de Astronomı́a de la Universidad Nacional Autónoma de México, Mexico
[email protected]
Alice Gabriela PÉREZ BLANCO , Centro de Investigaciones de Astronomı́a ”Francisco J. Duarte” (CIDA), , Venezuela
[email protected]
Angeles PEREZ-VILLEGAS, Centro de Radioastronomia y Astrofisica, UNAM, Mexico
[email protected]
Romina Paola PETRUCCI, Instituto de Astronomia y Fisica del Espacio (IAFE), Argentina
[email protected]
Barbara PICHARDO, Instituto de Astronomı́a, Universidad Nacional Autónoma de México (IA-UNAM), Mexico
[email protected]
Giuliano PIGNATA, Universidad Andrès Bello, Chile
[email protected]
Marcio do Carmo PINHEIRO, Universidade Federal da Fronteira Sul, Brazil
[email protected]
Rafael PINOTTI, Observatório do Valongo - Universidade Federal do Rio de Janeiro - UFRJ, Brazil
[email protected]
Olga PINTADO, INSUGEO-CONICET, Argentina
[email protected]
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Nelson PINTO-NETO, Centro Brasileiro de Pesquisas Fı́sicas, Brazil
[email protected]
Giovanni PINZON, Universidad Nacional de Colombia, Colombia
[email protected]
Priscilla Firmino POLIDO, Instituto Nacional de Pesquisas Espaciais, Brazil
[email protected]
Bogdan POPESCU, University of Cincinnati, USA, United States
[email protected]
Gustavo Frederico PORTO DE MELLO, Observatório do Valongo/Universidade Federal do Rio de Janeiro, Brazil
[email protected]
Ivanio PUERARI, INAOE, Mexico
[email protected]
Thomas H. PUZIA, Institute of Astrophysics, Pontificia Universidad Catolica, Chile
[email protected]
Carolina QUEIROZ DE ABREU SILVA, Universidade de São Paulo, Brazil
[email protected]
Bruno Correa QUINT, Universidade de São Paulo, Brazil
[email protected]
Seditsira Andrea QUINTERO VILLAMIZAR, Universidad Nacional de Colombia-Sede Bogotá, Colombia
[email protected]
Jonathan Alexander QUIROLA, Escuela Politécnica Nacional. Quito-Ecuador., Ecuador
[email protected]
Edgar Andre RAMIREZ ALONSO, IAG-USP, Brazil
[email protected]
Liz Angélica RAMOS MEDINA, Universidad Distrital Francisco Jose de Caldas, Colombia
[email protected]
Andres Felipe RAMOS PADILLA, Department of Physics, National University of Colombia. , Colombia
[email protected]
Aline Beatriz RAUBER, Universidade Federal de Santa Maria, Brazil
[email protected]
Henrique Marques REGGIANI, Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas (IAG)-Universidade de São
Paulo (USP), Brazil
[email protected]
Marı́a Camila REMOLINA GUTIÉRREZ, Universidad de los Andes, Colombia
[email protected]
Paolo Scarsi REPETTO, Laboratorio Nacional de Astrofisica, Brazil
[email protected]
Felipe Braga RIBAS, Observatório Nacional / MCTI, Brazil
[email protected]
Anderson de Oliveira RIBEIRO, Observatório Nacional, Brazil
[email protected]
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Brunno Augusto Gomes RIBEIRO, Pontificia universidade catolica de minas gerais, museu de ciencias naturais,
GAIA, Brazil
[email protected]
Evandro Martinez RIBEIRO, Observatório Nacional, Brazil
[email protected]
Filipe Batista RIBEIRO, UNESP - Rio Claro, Brazil
[email protected]
Nadili Louise RIBEIRO, Universidade de São Paulo, Brazil
[email protected]
Tiago RIBEIRO, Universidade Federal de Sergipe, Brazil
[email protected]
Tiago Vecchi RICCI, IAG - Universidade de São Paulo, Brazil
[email protected]
Rogemar A. RIFFEL, Universidade Federal de Santa Maria, Brazil
[email protected]
Rogerio RIFFEL, Universidade Federal do Rio Grande do Sul, Brazil
[email protected]
Leandro Rocha RÍMULO, Universidade de São Paulo, Brazil
[email protected]
Angel Erasmo RINCON, Universidad de Chile, Chile
[email protected]
Gustavo ROCHA DA SILVA, Universidade de São Paulo, Brazil
[email protected]
Javier A. RODÓN, European Southern Observatory, Chile
[email protected]
Bárbara H. G. RODRIGUES, Instituto Nacional de Pesquisas Espaciais (INPE), Brazil
[email protected]
Claudia Vilega RODRIGUES, INSTITUTO NACIONAL DE PESQUISAS ESPACIAIS, Brazil
[email protected]
Fábio Pinto RODRIGUES, Universidade Federal de Itajubá (UNIFEI), Brazil
[email protected]
Teresinha RODRIGUES, Observatório Nacional, Brazil
[email protected]
Irapuan RODRIGUES DE OLIVEIRA FILHO, Universidade do Vale do Paraı́ba, Brazil
[email protected]
Ana Maria RODRIGUEZ, Universidad Nacional de Colombia, Colombia
[email protected]
David RODRIGUEZ, Universidad de Chile, Chile
[email protected]
Facundo RODRIGUEZ, Instituto de Astronomı́a Teórica y Experimental- Universidad Nacional de Córdoba - CONICET,
Argentina
[email protected]
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Monica RODRIGUEZ, Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), Mexico
[email protected]
Christian David RODRÍGUEZ CAMARGO, Physics Department, National University of Colombia, Colombia
[email protected]
Alberto RODRIGUEZ-ARDILA, Laboratório Nacional de Astrofı́sica, Brazil
[email protected]
Fernando ROIG, Observatório Nacional, Brazil
[email protected]
Alejandra ROJAS, Pontificia Universidad Católica de Chile, Chile
[email protected]
Gustavo de Araujo ROJAS, Universidade Federal de São Carlos, Brazil
[email protected]
Karina Alexandra ROJAS, Departamento de Fı́sica y Astronomı́a, Universidad de Valparaı́so, Chile
[email protected]
Carlos Gerardo ROMÁN-ZÚÑIGA, Instituto de Astronomı́a, Unidad Académica en Ensenada, Universidad Nacional
Autónoma de México, Mexico
[email protected]
Alessio D. ROMEO, INAF, Italy, Italy
[email protected]
Alejandra Daniela ROMERO, Instituto de Fı́sica, UFRGS, Brazil
[email protected]
Julia Maria Torres ROQUETTE, Universidade Federal de Minas Gerais, Brazil
[email protected]
Deise Aparecida ROSA, Universidade do Vale do Paraı́ba- Univap, Brazil
[email protected]
Fernando Fabián ROSALES-ORTEGA, Instituto Nacional de Astrofı́sica, Óptica y Electrónica, Mexico
[email protected]
Marcelo Soares RUBINHO, Instituto de Astronomia, Geociência e Ciências Atmosféricas, Brazil
[email protected]
Beatriz Eugenia SABOGAL MARTÍNEZ, Universidad de los Andes, Bogotá, Colombia
[email protected]
Roberto SAITO, Universidade Federal de Sergipe, Brazil
[email protected]
Pedro SALAS, Instituto de Astrofı́sica, Facultad de Fı́sica, P. Universidad Católica de Chile, Chile
[email protected]
Andrea Sanchez SALDIAS, Departamento de Astronomia - Facultad de Ciencias - Universidad de la República, Uruguay
[email protected]
Dinalva A. SALES, Rochester Institute of Technology, United States
[email protected]
João Victor SALES SILVA, Observatório Nacional, Brazil
[email protected]
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Jorge Enrique SAMANES, Comisión Nacional de Investigación y Desarrollo Aeroespacial (CONIDA), Peru
[email protected]
Astrid Elizabeth SAN MARTIN, Universidad Andres Bello, Chile
[email protected]
Paula Andrea SÁNCHEZ, Universidad de Chile, Chile
[email protected]
Hillysson Bruno SANTOS, Universidade Estadual do Rio Grande do Norte, Brazil
[email protected]
Jéssica Pereira SANTOS, Universidade Federal de Sergipe, Brazil
[email protected]
Jullian Henrique Barbosa SANTOS, Universidade de São Paulo (USP), Brazil
[email protected]
Patricia SANTOS, Universidade Federal de Itajubá, Brazil
[email protected]
Rafael Gonzaga SANTOS , NAT - Universidade Cruzeiro do Sul, Brasil, Brazil
[email protected]
Reinaldo SANTOS DE LIMA, Instituto de Astronomia, Geofı́sica e C. Atmosféricas - Universidade de São Paulo, Brazil
[email protected]
Joao Francisco Coelho SANTOS JR., Universidade Federal de Minas Gerais, Brazil
[email protected]
Erick Rohan SANTOS OLIVEIRA MAGALHAES, Universidade Estadual de Santa Cruz, Brazil
[email protected]
Marı́a Victoria SANTUCHO, Instituto de Astronomı́a Téorico y Experimental (IATE-CONICET). , Argentina
[email protected]
Maria de Fátima Oliveira SARAIVA , Universidade Federal do Rio Grande do Sul, Brazil
[email protected]
Christian Andres SARMIENTO CANO , Universidad Industrial de Santander, Colombia
[email protected]
Tiago Abreu SAURIN, Universidade Federal do Rio Grande do Sul, Instituto de Fı́sica, Departamento de Astronomia,
Brazil
[email protected]
Jaderson Silva SCHIMOIA, Universidade Federal de Santa Maria, Brazil
[email protected]
Mischa SCHIRMER, Gemini Observatory, Chile
[email protected]
Marielli de Souza SCHLICKMANN, Universidade Federal de Santa Catarina, Brazil
[email protected]
Wagner SCHLINDWEIN, Universidade Federal de Santa Catarina, Brazil
[email protected]
William SCHOENELL, Instituto de Astrofı́sica de Andalucı́a - CSIC, Spain
[email protected]
xxxvi
Matthias R. SCHREIBER, Universidad de Valparaiso, Departamento de Fisica y Astronomia, Chile, Chile
[email protected]
Steve SCHULZE, Pontificia Universidad Católica de Chile , Chile
sschul[email protected]
Daiane Breves SERIACOPI, Universidade de São Paulo, Brazil
[email protected]
Diah SETIA GUNAWAN, Joint ALMA Office, Santiago, Chile, Chile
[email protected]
Mario Agustı́n SGRÓ, Instituto de Astronomı́a Teórica y Experimental - UNC - CONICET, Argentina
[email protected]
Costantino SIGISMONDI, Observatório Nacional/MCTI & ICRANet/Sapienza Universitá di Roma and Ateneo Pontificio
Regina Apostolorum, Italy
[email protected]
André Rodrigo da SILVA, Universidade Federal de São Paulo, Brazil
[email protected]
Gabriel Gonçalves SILVA, Universidade Federal de São Carlos, Brazil
[email protected]
José Ronaldo Pereira da SILVA, Universidade do Estado do Rio Grande do Norte, Brazil
[email protected]
Karleyne SILVA, Instituto Nacional de Pesquisas Espaciais, INPE, Brazil
[email protected]
Raquel Boesso SILVA, Observatório do Valongo - Universidade Federal do Rio de Janeiro, Brazil
[email protected]
Thais Santos SILVA, Universidade de São Paulo, Brazil
[email protected]
Vinicius Branco SILVA, Universidade de São Paulo, Brazil
[email protected]
José Sergio SILVA CABRERA, Observatório Nacional, Brazil
[email protected]
Carlos Roberto SILVEIRA, Universidade de São Paulo, Brazil
[email protected]
Marcelo Kenji SIME, Universidade de São Paulo, Brazil
[email protected]
Mirko SIMUNOVIC, Pontificia Universidad Catolica de Chile, Chile
[email protected]
Anna SIPPEL, ESO Santiago / Swinburne University, Australia, Chile
[email protected]
Marcos Felipe Faria Terra SIQUEIRA, Universidade Federal de Itajubá, Brazil
[email protected]
Cesar SIQUEIRA MELLO, IAG - Universidade de São Paulo, Brazil
[email protected]
xxxvii
Camila Maria SITKO, Universidade Estadual de Londrina (UEL), Brazil
[email protected]
Rodolfo SMILJANIC, Nicolaus Copernicus Astronomical Center, Poland
[email protected]
Braulio Batista SOARES, Universidade do Estado do Rio Grande do Norte, Brazil
[email protected]
Laerte SODRE , USP - Instituto de Astronomia, Geofisica e Ciências Atmosfericas, Brazil
[email protected]
Piera Andrea SOTO KING, Universidad de La Serena, Chile
[email protected]
Alana Paixão de SOUSA, Universida Federal de Minas Gerais, Brazil
[email protected]
Diogo Martins SOUTO, Observatorio Nacional - MCT, Brazil
[email protected]
Julio César SPAGNOTTO, Universidad Nacional de La Pampa, Argentina
[email protected]
Patricia Figueiró SPINELLI, Museu de Astronomia e Ciências Afins (MAST), Brazil
[email protected]
Grazyna STASINSKA, Observatoire de Paris, France
[email protected]
Katrien Christine STEENBRUGGE, Instituto de Astronomia, Universidad Catolica del Norte & Department of Physics,
University of Oxford, Chile
[email protected]
João E. STEINER, Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas - USP, Brazil
[email protected]
Thaisa STORCHI-BERGMANN, Instituto de Fı́sica, Universidade Federal do Rio Grande do Sul, Brazil
[email protected]
Laura Andrea SUAD, Instituto Argentino de Radioastronomı́a (IAR)., Argentina
[email protected]p.edu.ar
Edilberto SUAREZ TORRES, Universidad Distrital ”Francisco José de Caldas”, Facultad de Ingenierı́a, Colombia
[email protected]
Katalin TAKATS, Universidad Andres Bello, Chile
[email protected]
Gonzalo TANCREDI, Depto. Astronomia, Fac. Ciencias, Uruguay
[email protected]
Eduardo TELLES, Observatorio Nacional, Brazil
[email protected]
Ramachrisna TEXEIRA, IAG-USP, Brazil
[email protected]
Patricia B. TISSERA, Institute for Astronomy and Space Physics, Argentina
[email protected]
xxxviii
Laura TORIBIO SAN CIPRIANO, Instituto de Astrofı́sica de Canarias, Spain
[email protected]
Carlos Alberto O. TORRES, Laboratório Nacional de Astrofı́sica (LNA/MCTI), Brazil
[email protected]
Andres David TORRES CAÑAS , National University of Colombia. Physics School. Sciences Faculty, Natural Sciences
Museum of La Salle. A project of ITM. Astronomical Observatory, Colombia
[email protected]
Juanita TORRES ZAFRA, Instituto de Astrofı́sica de La Plata, Argentina
[email protected]
Sergio TORRES-FLORES, Universidad de La Serena, Chile
[email protected]
Silvia TORRES-PEIMBERT, UNIVERSIDAD NACIONAL AUTONOMA DE MEXICO, Mexico
[email protected]
Josué de Jesús TREJO-ALONSO, Universidad de Guanajuato, Mexico
[email protected]
Amy Alexandra TYNDALL, ESO, Chile / JBCA, UK, Chile
[email protected]
Fernanda URRUTIA, universidade de sao paulo, Brazil
[email protected]
Bruna VAJGEL, Observatorio do Valongo, Universidade Federal do Rio de Janeiro, Brazil
[email protected]
Natalia VALE ASARI, Universidade Federal de Santa Catarina, Brazil
[email protected]
Adriana VALIO, CRAAM, Universidade Presbiteriana Mackenzie, Brazil
[email protected]
David VALLS-GABAUD, Observatoire de Paris, France
[email protected]
Maria Eugenia VARELA, Instituto de Ciencias Astronomicas de la Tierra y del Espacio (ICATE), Argentina
[email protected]
Santiago VARGAS DOMÍNGUEZ, Universidad de los Andes, Colombia
[email protected]
Javier VASQUEZ, Instituto Argentino de Radioastronomı́a, Argentina, Argentina
[email protected]
Sebastian VELASCO, Universidad de los Andes, Colombia
[email protected]
Román Rodrigo VENA VALDARENAS, Instituto de Astronomı́a Teórica y Experimental, Argentina
[email protected]
Rafael Jonathan Camilo VERA, Universidad Nacional de Colombia, Colombia
[email protected]
Celia Anahi VERDUGO, Observatoire de Paris, France
[email protected]
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Mariela Cristina VIEYTES, Universidad de Tres de Febrero, Instituto de Astronomı́a y Fı́sica del Espacio, Argentina
[email protected]
Carolina Susana VILLARREAL D’ANGELO, Instituto de Astronomı́a Teórica y Experimental (IATE), Argentina
[email protected]
Marcos Rincon VOELZKE, Universidade Cruzeiro do Sul, Brazil
[email protected]
Zhong WANG, Chinese Academy of Sciences South America Center for Astronomy (CASSACA), Chile
[email protected]
Ariel WERLE, Universidade Federal de Santa Catarina, Brazil
[email protected]
Othon Cabo WINTER, Universidade Estadual Paulista - UNESP, Brazil
[email protected]
Eduardo Luann WOJCIKIEWICZ, Universidade Federal de Santa Catarina, Brazil
[email protected]
Henrique Scemes XAVIER, Instituto de Fı́sica da Universidade de São Paulo (IFUSP), Brazil
[email protected]
Jincheng YU, Pontificia Universidad Católica de Chile, Chile
[email protected]
Alessandra ZANAZZI, INAF - Osservatorio Astrofisico di Arcetri, Italy
[email protected]
Luis A. ZAPATA, Centro de Radioastronomia y Astrofisica, UNAM, Mexico
[email protected]
Libardo ZERPA, Centro de Investigaciones de Astronomia ”Francisco José Duarte” (CIDA) y Universidad de Los Andes
(ULA), Venezuela
[email protected]
Hans ZINNECKER, SOFIA Science Center, NASA-Ames, United States
[email protected]
Manuela ZOCCALI, Pontificia Universidad Catolica de Chile, Chile
[email protected]
xl
Review & Invited Talks
1
Distribution and Origin of Hot Planets
C. BeaugeB1
Close-in (or Hot) planets, usually defined as those having semimajor axes a < 0.1 AU (or orbital periods P <
10 days), are the easiest to detect, both with radial velocity (RV) surveys and transits. More than 300 members
are currently known, and a much larger number of candidates has been proposed by the Kepler team. Since
it is believed that these bodies cannot have been formed in-situ, they constitute an interesting population
from which to derive information about orbital migration and dynamical evolution of planetary systems in
general.
In this talk we review some recent results on the dynamical characteristics of close-in planets, including the
existence of both resonant and near-resonant configurations, planet multiplicity, eccentricity distribution
and inclinations with respect to the stellar equator. We discuss how disk-induced migration, planet-planet
scattering and tidal effects may help us explain several of these dynamical traits, although others are still
poorly understood. Finally, we analyze the similarities and differences found in small (Earth to Neptune)
and large (Jovian) size planets, and how these may reflect different evolutionary histories.
B
1
[email protected]
Instituto de Astronomia Teorica y Experimental, Observatorio Astronomico, Universidad Nacional de Cordoba, Argentina
Planetary systems
Review & Invited Talks
Impact studies in Latin America
Gonzalo TancrediB1
The research about impact process of extraterrestrial bodies onto the Earth is a new subject in only a few
institutes in Latin America. A proof of that is the scarcity of recognized impact structures in the region. Nevertheless, we have among the most interesting features on Earth, like the crater strewn fields of Campo del
Cielo (Chaco, Argentina) and Bajada del Diablo (Neuquén, Argentina); and the recently formed small crater
of Carancas (Perú). These cases have questioned several ideas about the nature of the impacting objects:
monolithic vs. agglomerate; as well as the survival of the objects in the passage through the atmosphere.
These questions have important implications regarding the plans to deflect a threatening asteroid and the
risk and consequences of small impactors. A few groups in the region have been involved in field research in
those craters, as well as experimental and theoretical studies about impact processes and deflection mechanisms. We will highlight the most relevant results on this growing scientific field.
B
1
[email protected]
Depto. Astronomia, Fac. Ciencias, Montevideo, URUGUAY
4
Review & Invited Talks
Teaching and outreach
A New Chinese Astronomy Center in Chile
Wang, Z.B1,2,3 ; Huang, J.-S.1,2,3
As part of a new initiative launched by the Chinese Academy of Sciences (CAS) to expand its collaboration
with the rest of the world, a CAS South America Center for Astronomy (CASSACA, also known as China-Chile
Joint Center for Astronomy) has recently been established in Santiago, Chile. I will introduce the central
mission of this Center, and discuss the prospect of supporting collaborative research between Chinese astronomers and their Latin American colleagues.
B
1
2
2
[email protected]
Chinese Academy of Science’s South American Center for Astronomy
National Astronomical Observatories, Chinese Academy of Sciences
Harvard-Smithsonian Center for Astrophysics
5
Stars
Review & Invited Talks
Supergiants, Stellar Winds and Mass-loss
Cidale, L.B1,2
The knowledge of the wind properties and the mass loss rate in massive stars is a milestone in the stellar
evolution and the chemical composition of the interestellar medium. Our current view of stellar winds reveals they are often highly variable and inhomogeneous. We review here the wind structure of early-type
stars (the wind clumping and the weak-wind problems) and the peculiar circumstellar environment around
some short-lived phases of evolved massive stars (i.e.: LBVs and B[e] supergiants). Accurate mass loss rate
estimates are crucial keys to discuss the importance of different triggering mechanisms in driving the wind.
B
1
2
[email protected]
Instituto de Astrofı́sica La Plata
Facultad de Ciencias Astronómicas y Geofı́sicas, Universidad de La Plata
6
Review & Invited Talks
ISM
Abundance determinations in ionized nebulae and their sensitivity to temperature
Rodriguez, M.B1 ; Manso-Sainz, R.2
Our main source of uncertainty in the determination of chemical abundances in H II regions and planetary
nebulae arises from a discrepancy: the abundances implied by recombination lines are larger than those
implied by collisionally excited lines. Most objects show a factor of 2 discrepancy, but some planetary nebulae display much higher discrepancies. I will discuss the possible explanations of this effect, focusing on
the latest: I will describe what kind of deviations from a Maxwellian electron energy distribution are needed
in order to reproduce the measured abundance discrepancies. I will explore the parallelisms between the
three explanations of the discrepancy that are based on the sensitivity to temperature of collisionally excited
lines, namely, deviations from a Maxwellian energy distribution, temperature fluctuations, and the presence
of metal-rich inclusions. I will show some evidence that at least one of these mechanisms is acting in H II
regions.
B
1
2
[email protected]
Instituto Nacional de Astrofisica, Optica y Electronica (INAOE)
Instituto de Astrofisica de Canarias (IAC)
7
Stars
Review & Invited Talks
Solar Transient Activity: Magnetic Energy Release and Topology
Mandrini, C. H.B1
The energy released during transient atmospheric events in the Sun is contained in current-carrying magnetic fields that have emerged after traversing the solar convective zone. Once the magnetic flux reaches
the photosphere, it may be further stressed via motions in this lower atmospheric layer. Magnetic field reconnection is thought to be the mechanism through which the stored magnetic energy is transformed into
kinetic energy of accelerated particles and mass flows, and radiative energy along the whole electromagnetic
spectrum. Though this mechanism is efficient only at very small spatial scales, it may imply a large-scale restructuring of the magnetic field which is inferred from the combined analysis of observations, models of the
coronal magnetic field, and computation of its topology. The consequences of energy release include events
that range from nano-flares, still below our present observational spatial resolution, to powerful flares that
may be accompanied by the ejection of large amounts of plasma and magnetic field in events called coronal mass ejections (CMEs). We will review key observational signatures of flares and CMEs on the Sun and
discuss how the computation and analysis of the magnetic field topology, applied to the widest variety of
observed magnetic configurations, can be used to identify the energy release locations and their physical
characteristics.
B
1
[email protected]
Instituto de Astronomı́a y Fı́sica del Espacio, IAFE
8
Review & Invited Talks
Planetary systems
The SNC Meteorites
Varela, M. E.B1
The SNC (Shergotty-Nakhla-Chassigny) group, are achondritic meteorites. Of all SNC meteorites recognized
up to date, shergottites are the most abundant group. The petrographic study of Shergotty began several
years ago when Tschermak, (1872) identified this rock as an extraterrestrial basalt. Oxygen isotopes in SNC
meteorites indicate that these rocks are from a single planetary body (Clayton and Mayeda, 1983). Because
the abundance patterns of rare gases trapped in glasses from shock melts (e.g., Pepin, 1985) turned out to be
very similar to the Martian atmosphere (as analyzed by the Viking landers, Owen, 1976), the SNC meteorites
are believed to originate from Mars (e.g. McSween, 1994). Possibly, they were ejected from the Martian surface either in a giant impact or in several impact events (Meyer 2006). Although there is a broad consensus
for nakhlites and chassignites being -1.3Ga old, the age of the shergottites is a matter of ongoing debates.
Different lines of evidences indicate that these rocks are young (180Ma and 330-475Ma), or very old (> 4Ga).
However, the young age in shergottites could be the result of a resetting of these chronometers by either
strong impacts or fluid percolation on these rocks (Bouvier et al., 2005-2009). Thus, it is important to check
the presence of secondary processes, such as re-equilibration or pressure-induce metamorphism (El Goresy
et al., 2013) that can produce major changes in compositions and obscure the primary information. A useful
tool, that is used to reconstruct the condition prevailing during the formation of early phases or the secondary processes to which the rock was exposed, is the study of glass-bearing inclusions hosted by different
mineral phases. I will discuss the identification of extreme compositional variations in many of these inclusions (Varela et al 2007-2013) that constrain the assumption that these objects are the result of closed-system
crystallization. The question then arises whether these inclusions can be considered reliable samples of the
fluid/melt that was originally trapped.
B
1
[email protected]
Instituto de Ciencias Astronómica de la Tierra y del Espacio (ICATE)
9
Instrumentation
Review & Invited Talks
New Opportunities with the Gemini Observatory
M. BoccasB1
Gemini Observatory’s associate director for development Maxime Boccas will present an update of the facility and introduce some new opportunities for astronomers at Gemini. Gemini operates twin 8-m telescopes,
one in Hawaii and the other in Chile. The departure of the UK from Gemini’s international partnership at the
end of 2012 provided the chance to re-evaluate the services offered to Gemini users and opened new opportunities in two domains. First, Gemini will welcome discussions with groups wanting to bring their own instruments for campaigns. This visiting instrument program will complement the suite of workhorse instruments offered by the Observatory, and will allow scientific breakthroughs not possible with the regular suite
of instruments. Second, the Gemini observatory will be offering cross-partnership large or long programs.
From 2014 on, Gemini will be dedicating 20collaborative programs selected through a yearly call. Gemini is
also looking at the possibility of offering some fraction of time in a fast turn-around mode, as well as ”eavesdropping” for queue observing. We remain very interested in having astronomers visit the telescopes. In
addition to these two major initiatives, several new instruments have appeared in 2013: Flamingos-2 and
the Gemini Multi-conjugate adaptive optics System (GeMS) are being offered for science, and the Gemini
Planet Imager (GPI) has arrived on Cerro Pachon.
B
1
[email protected]
Gemini Observatory
10
Review & Invited Talks
AGN
Active Galactic Nuclei
Arévalo, P.B1
Accreting supermassive black holes have had a large impact in the evolution of their host galaxies, and even
inject significant energy into their host cluster of galaxies. Although the black hole’s influence in these large
structures is evident, the central engine itself is remarkably difficult to observe. Their extremely compact
nature makes it impossible to resolve the final source of fueling, the accretion disc, although interferometric
observations have started to reveal important details of the material directly outside this region. In this talk
I will review the techniques that have shed light into the structure and behavior of these central engines in
the quest to find out how black hole grow.
B
1
[email protected]
Pontificia Universidad Católica, Chile
11
Star formation
Review & Invited Talks
Diversity of protoplanetary disks in stellar clusters: the case of the sigma Orionis
cluster
Hernández J.B1 ; Calvet N.2 ; Mauco K.2 ; Ballesteros J.4 ; Perez A.1 ; Briceño C.1 ; Hartmann L.2 ; Olguin L.3 ; Contreras M.4 ;
Allen L.5 ; Espaillat C.6
The Orionis cluster is a natural laboratory to study stars and protoplanetary disks in the first stages of their
evolution. This cluster is relatively near (Distance ⇠400 pc) and the extinction is low (AV <
⇠ 0.5 mag) and thus
enable us to study young stars in a entire range of masses, from its most massive star (O9.5 type star) to the
lowest mass objects, such as brown dwarfs and free-floating planets. Recently, we have obtained the largest
and most homogeneous spectroscopic characterization to date of stars belong to this cluster. This information is a corner stone to derive stellar parameter. Of particular interest are stars that exhibit infrared excesses
produced by protoplanetary disks. Since the
Orionis cluster has an evolutionary stage in which mech-
anisms of disk dispersal have affected substantially its disk population, we observe large diversity of disks
in this stellar cluster (e.g.,optically thick full disks, pre-transitional disks, transitional disks, homogeneusly
depleted disks and debris disks). More than 100 stars bearing protoplanetary disks have been detected in
the
Orionis cluster with the disk census presented few years ago using IRAC and MIPS observations. In
this contribution, we present an overview of the latest results of an ongoing study of the disk population in
the
Orionis cluster combining Hershel-PACS observation, IRS spectroscopic data for selected targets and
theoretical models of disk evolution. In order to get a better understand of how disk evolves from optically
thick full disks to debris disks, these results will be combined with similar studies that we are doing in more
dispersed and older regions of the Orion OB1a and OB1b sub association.
B
1
2
3
4
5
6
[email protected]
Centro de Investigaciones de Astronomı́a, Mérida, Venezuela
Department of Astronomy, University of Michigan, Ann Arbor, MI 48109, US
Depto. de Investigación en Fı́sica, Universidad de Sonora, Sonora, México
Instituto de Astronomı́a, Universidad Nacional Autónoma de México, Ensenada, BC, México
NOAO, US
Harvard-Smithsonian Center for Astrophysics, US
12
Review & Invited Talks
Stars
White Dwarf Stars
S. O. KeplerB1
White dwarfs are the evolutionary endpoint for nearly 95% of all stars born in our Galaxy, the final stages of
evolution of all low- and intermediate mass stars, i.e., main sequence stars with masses below (8.5 ± 1.5) M ,
depending on metallicity of the progenitor, mass loss and core overshoot. Massive white dwarfs are intrinsically rare objects, tand produce a gap in the determination of the initial vs. final mass relation at the high
mass end (e.g. Weidemann 2000 A&A, 363, 647; Kalirai et al. 2008, ApJ, 676, 594; Williams, Bolte & Koester
2009, ApJ, 693, 355). Main sequences stars with higher masses will explode as SNII (Smartt S. 2009 ARA&A, 47,
63), but the limit does depend on the metallicity of the progenitor. Massive white dwarfs are probably SNIa
progenitors through accretion or merger. They are rare, being the final product of massive stars (less common) and have smaller radius (less luminous). Kepler et al. 2007 (MNRAS, 375, 1315), Kleinman et al. 2013
(ApJS, 204, 5) estimate only 1-2% white dwarfs have masses above 1 M . The final stages of evolution after
helium burning are a race between core growth and loss of the H-rich envelope in a stellar wind. When the
burning shell is exposed, the star rapidly cools and burning ceases, leaving a white dwarf. As they cool down,
the magnetic field freezes in, ranging from a few kilogauss to a gigagauss. Peculiar type Ia SN 2006gz, SN
2007if, SN 2009dc, SN 2003fg suggest progenitors in the range 2.4
2.8 M , and Das U. & Mukhopadhyay B.
(2012, Phys. Rev. D, 86, 042001) estimate that the Chandrasekhar limit increases to 2.3 2.6 M for extremely
high magnetic field stars, but differential rotation induced by accretion could also increase it, according to
Hachisu I. et al. 2012 (ApJ, 744, 69). Garcı́a-Berro et al. 2012, ApJ, 749, 25, for example, proposes double
degenerate mergers are the progenitors of high-field magnetic white dwarfs. We propose magnetic fields
enhance the line broadening in WDs, causing an overestimated surface gravity, and ultimately determine if
these magnetic fields are likely developed through the star’s own surface convection zone, or inherited from
massive Ap/Bp progenitors. We discovered around 20 000 spectroscopic white dwarfs with the Sloan Digital
Sky Survey (SDSS), with a corresponding increase in relatively rare varieties of white dwarfs, including the
massive ones (Kleinman et al. 2013, ApJS, 204, 5, Kepler et al. 2013, MNRAS, 439, 2934). The mass distributions of the hydrogen-rich (DA) measured from fitting the spectra with model atmospheres calculated using
unidimensinal mixing lenght-theory (MLT) shows the average mass (as measured by the surface gravity) increases apparently below 13 000K for DAs (e.g. Bergeron et al. 1991, ApJ, 367, 253; Tremblay et al. 2011, ApJ,
730, 128; Kleinman et al. 2013). Only with the tridimensional (3D) convection calculations of Tremblay et
al. 2011 (A&A, 531, L19) and 2013 (A&A, 552, 13; A&A, 557, 7; arXiv 1309.0886) the problem has finally been
solved, but the effects of magnetic fields are not included yet in the mass determinations. Pulsating white
dwarf stars are used to measure their interior and envelope properties through seismology, and together with
the luminosity function of white dwarf stars in clusters and around the Sun are valuable tools for the study
of high density physics, and the history of stellar formation.
B
1
[email protected]
Universidade Federal do Rio Grande do Sul, Brazil
13
Planetary systems
Review & Invited Talks
The evolution of protoplanetary disk
Matthias R. SchreiberB1
The evolution of protoplanetary disks is essential for the star and planet formation process. While we have
discovered several mechanisms that are likely to drive the evolution of disks, e.g. grain growth, photoevaporation, planet formation, or binarity, we still struggle to understand their relative importance for the global
evolution of protoplantary disks and to relate them to observations. I will review recent progress based on
large infrared surveys of star forming regions, highlight spectacular discoveries made with ALMA, discuss
the possible detections of forming planets still embedded in their disks, and outline the future prospects of
this rapidly advancing research field.
B
1
[email protected]
Universidad de Valparaiso, Chile
14
Review & Invited Talks
Galaxies
Galaxies at High Redshift
Franz. E. BauerB1
Recent years have seen tremendous progress in finding and charactering star-forming galaxies at high redshifts across the electromagnetic spectrum, giving us a more complete picture of how galaxies evolve, both
in terms of their stellar and gas content, as well as the growth of their central supermassive black holes. A
wealth of studies now demonstrate that star formation peaked at roughly half the age of the Universe and
drops precariously as we look back to very early times, and that their central monsters apparently growth
with them. At the highest-redshifts, we are pushing the boundaries via deep surveys at optical, X-ray, radio
wavelengths, and more recently using gamma-ray bursts. I will review some of our accomplishments and
failures.
Telescope have enabled Lyman break galaxies to be robustly identified, but the UV luminosity function
and star formation rate density of this population at z = 6
8 seems to be much lower than at z = 2
4.
High escape fractions and a large contribution from faint galaxies below our current detection limits would
be required for star-forming galaxies to reionize the Universe. We have also found that these galaxies have
blue rest-frame UV colours, which might indicate lower dust extinction at z > 5. There has been some
spectroscopic confirmation of these Lyman break galaxies through Lyman-↵ emission, but the fraction of
galaxies where we see this line drops at z > 7, perhaps due to the onset of the Gunn-Peterson effect (where
the IGM is opaque to Lyman-↵).
B
1
[email protected]
Pontificia Universidad Católica de Chile
15
Galaxies
Review & Invited Talks
The star formation history of galaxies in the CALIFA survey
Rosa González DelgadoB1 ; Roberto Cid Fernandes2 ; Enrique Pérez1 ; Ruben Garcı́a Benito1 ; André Amorim1,2 ; Clara
Cortijo1 ; Rafael López Fernández1 ; Sebastian Sánchez1
The spatially resolved star formation history (SFH) of galaxies contains fundamental information to understand how the galaxies formed and evolve. We apply the fossil record method based on spectral synthesis
techniques to recover the SFH resolved in space and time for more than 200 galaxies from the CALIFA survey, which is gathering Integral Field Spectroscopy over the optical range and up to radial distances of 3 half
light radii (HLR) of local (z = 0.005–0.03) galaxies. This CALIFA sub-sample is well distributed in the colormagnitude diagram and contains a fair representation from the ellipticals through the bulge dominated to
the pure disk galaxies. In terms of stellar mass, the galaxies are distributed between Log M (Msun)= 9 to 12
with a peak in galaxies like the MW and M31. We investigate the SFH of galaxies and their trends of the radial
structure as a function of the galaxy stellar mass and morphology. We show how the different galactic spatial
sub-components (”bulge” and ”disk”) grow their stellar mass over time. We find that star formation history
of bulges is more fundamentally related to the stellar galaxy mass, and in contrast disks is related with the
local stellar mass surface density. We also obtain the spatially averaged and integrated galaxy properties, and
how they are related with the properties at 1HLR.
B
1
2
[email protected]
Instituto de Astrofı́sica de Andalucı́a
Universidade Federal de Santa Catarina
16
Review & Invited Talks
Instrumentation
ESO: Present and Future
Andreas KauferB1
ESO is an intergovernmental organization for astronomy founded in 1962 by five countries. It currently has
14 Member States in Europe with Brazil poised to join as soon as the Accession Agreement has been ratified. Together these countries represent approximately 30 percent of the world’s astronomers. ESO operates
optical/infrared observatories on La Silla and Paranal in Chile, partners in the sub-millimeter radio observatories APEX and ALMA on Chajnantor and is about to start construction of the Extremely Large Telescope on
Armazones.
La Silla hosts various robotic telescopes and experiments as well as the NTT and the 3.6m telescope. The
former had a key role in the discovery of the accelerating expansion of the Universe and the latter hosts
the ultra-stable spectrograph HARPS which is responsible for the discovery of nearly two-thirds of all confirmed exoplanets with masses below that of Neptune. On Paranal the four 8.2m units of the Very Large Telescope, the Interferometer and the survey telescopes VISTA and VST together constitute an integrated system
which supports 16 powerful facility instruments, including adaptive-optics-assisted imagers and integralfield spectrographs, with half a dozen more on the way and the Extremely Large Telescope with its suite of
instruments to be added in about ten years time. Scientific highlights include the characterisation of the
supermassive black hole in the Galactic Centre, the first image of an exoplanet, studies of gamma-ray bursts
enabled by the Rapid Response Mode and milliarcsec imaging of evolved stars and active galactic nuclei. The
single dish APEX antenna, equipped with spectrometers and wide-field cameras, contributes strongly to the
study of high-redshift galaxies and of star- and planet-formation. Early Science results obtained with the
ALMA interferometer already demonstrate its tremendous potential for observations of the cold Universe.
The review will summarize the entire ESO program and consider the next steps.
B
1
[email protected]
ESO
17
Stellar systems
Review & Invited Talks
Galactic Dynamics: Origin, History, Present and Prospect
Barbara PichardoB1
In this talk I will present a travel through the history and main contributions to astrophysical development
of the galactic dynamics discipline, passing by the most successful predictions and models, finishing with an
integral vision of what is known from the Milky Way structure from it dynamics and the prospects with the
new large scale surveys to understand it in the next decades.
B
1
[email protected]
Instituto de Astronomı́a, Universidad Nacional Autónoma de México (UNAM)
18
Review & Invited Talks
AGN
Determining the distances of the structures surrounding super-massive black holes
Steenbrugge, K. C.B1,2
The surroundings of super-massive black holes located in the centers of active galaxies is complex with many
components, such as the accretion disk, the corona, broad line region, the reflection component, the torus
and warm absorber, which is outflowing ionized plasma. The distance from the black hole, the size and
geometry of most of these components is poorly constrained. To constrain some of these physical parameters we used the technique of time-resolved UV and X-ray spectroscopy. We obtained optical to gamma-ray
spectra and lightcurves over 100 days for Mrk 509, one of the brightest AGN in the X-ray band. The most important conclusions are that the corona is consistent with an optically thick and relatively low temperature
layer on top of the accretion disk, compto-ionizing the accretion disk photons. The reflection component,
easily detected through the broad Fe K↵ line, is located between 40-1000 gravitational radii from the black
hole. Two of the warm absorber components have a distance of ⇠10 pc and for the others the distance is
larger than 70 pc, and all are thus located well outside the broad line region. From these distances we can
constrain the importance of these outflows on galactic evolution through feedback and the recycling of metals in the galaxy.
B
1
2
[email protected]
Instituto de Astronomia, Universidad Catolica del Norte, Avenida Angamos 0610, Antofagasta, Chile
Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH, UK
19
Cosmology
Review & Invited Talks
Testing Fundamental Hypotheses in Cosmology
J. S. AlcanizB1
Testing fundamental hypotheses in cosmology constitutes an important task for fundamental physics since
any violation of them would be a clear evidence of new physics. In this talk, we review some of these hypotheses and discuss the possibility of testing the so-called cosmic distance duality relation (CDDR). We derive a
new relation involving current measurements of the gas mass fraction of galaxy clusters from the SunyaevZeldovich effect fSZE and x-ray surface brightness fX
ray
observations, i.e., fSZE = ⌘fX
ray , where ⌘
quan-
tifies deviations from the CDDR. Since this latter expression is valid for the same object in a given galaxy
cluster sample, its application to current data removes possible contaminations from different systematics
error sources and redshift differences involved in luminosity and angular diameter distance measurements.
We use the most recent fX
ray
and fSZE data to test the CDDR as an exact principle in Nature and discuss
the results in the light of some possible physics mechanisms of CDDR violation.
B
1
[email protected]
Observatório Nacional/MCTI
20
Review & Invited Talks
Cosmology
Multiple-tracer surveys of the large-scale structure of the Universe
L. Raul AbramoB1
New astrophysical surveys are starting to detect galaxies of many different types in massive numbers. At the
same time, these surveys are also mapping with exquisite accuracy the different environments where these
galaxies live. I will show that redshift surveys that map several different tracers of large-scale structure (e.g.,
galaxies of different luminosities, or halos of different masses) are a new leap forward for Cosmology. These
surveys can even appear to overcome the fundamental statistical limitation known as cosmic variance. I will
show how this is in fact possible, and how we can enhance constraints on cosmological parameters when
a given survey has a sufficient number of tracers of large-scale structure of different biases. I will make the
case for the multiple-tracer approach using the concrete example of J-PAS (the Javalambre PAU Astrophysical
Survey), one of the most promising redshift surveys of the near future.
B
1
[email protected]
Physics Institute, University of Sao Paulo
21
Instrumentation
Review & Invited Talks
Mmtron
de Graauw, T.B1
Millimetron is a 10-meter cooled space observatory that is optimized for the far-infrared and submm wavelength range. The facility has two operating modes: one can operate as a single-dish observatory or as an
element of a space-earth VLBI system. It will have scientific capabilities that can address various key problems in astronomy and astrophysics such as the formation and evolution of stars and planetary systems,
evolution of galaxies, quasars etc.. The telescope will be deployed in space and the panels of the primary
mirror are to be adjustable to achieve an rms accuracy less than 10 micron. The telescope and instrument
compartment will be cooled down to 4.5K by passive cooling and mechanical coolers. The instrument package is to include a set of heterodyne receivers operating in several bands between from 500 and 5000 GHz, a
submm array camera/spectrometer and a mm array camera/spectrometer covering 50 micron to 3 mm. Millimetron is proposed as a Russian-led mission and is to include a wide international collaboration. Currently,
the mission scheduled to be launched in 2020.
B
1
[email protected]
ALMA
22
Review & Invited Talks
Instrumentation
The SOFIA Airborne Infrared Observatory - first science highlights and future science
potential
Hans ZinneckerB1
SOFIA, short for Stratospheric Observatory for Infrared Astronomy, is a Boeing 747SP aircraft with a 2.7m
telescope flying as high as 45000 ft in the stratosphere above 99 percent of the precipitable water vapor.
SOFIA normally operates from its base in Palmdale, California, and a typical observing flight lasts for 10
hours before returning to base.
SOFIA has started astronomical observations in Dec 2010 and has completed some 30 early science flights
in 2011, delivering a number of exciting results and discoveries, both in mid-infrared imaging (5-40mu) and
in far-infrared (THz) heterodyne high-resolution spectroscopy which were published in mid-2012 in special
issues of ApJ Letters and A & A, respectively. Meanwhile, in July 2013, as part of Cycle 1, SOFIA has deployed
to New Zealand for a total of 9 flights (all of them successful) and has observed key targets in the southern
hemisphere at THz frequencies, including star forming regions in the Large and Small Magellanic Clouds.
In this talk, I will present a few highlights of SOFIA early science and its future potential, when the full
suite of 7 instruments will be implemented by the time of full operations in 2015. As Herschel ran out of
cryogens in April 2013, SOFIA will be the premier FIR-astronomical facility for many years to come. Synergies
with ALMA and CCAT must be explored.
SOFIA is a major bilateral project between NASA and the German Space Agency (DLR), however as an
international observatory it offers observing time to the whole astronomical community world-wide, not
only to the US and German primary partners.
B
1
[email protected]
SOFIA Science Center at NASA-Ames, USA and DSI at Univ. of Stuttgart, Germany
23
Star formation
Review & Invited Talks
Star and planet formation in the era of the submillimeter observatories SMA/ALMA
Luis ZapataB1
In this talk, I will present the recent advances and challenges on the star and planet formation studies in
era of the submillimeter observatories: the Submillimeter Array (SMA) and the Atacama Large Millimeter/Submillimeter Array (ALMA). These observatories now provide angular resolutions similar to those obtained in the optical regimen allowing to study the obscured innermost parts of the circumstellar disks where
the planet and star formation are taken place. When ALMA is finished, its sensivity and high angular resolution might reveal planets around close-by young stars just in the process of formation. This will open a new
venue for the understanding on the origin of our own solar system.
B
1
[email protected]
Centro de Radioastronomı́a y Astrofisica (CRyA), UNAM
24
Short Talks
25
Planetary Systems
PS -1
Multi-band characterization of hot jupiters using OPD data
M. MoyanoB1 ; L. A. Almeida2,3 ; F. Jablonski3
If an exoplanet’s orbit is oriented along the line of sight, it is possible to observe periodic transits. The study
of transiting extrasolar planets (TEPs) provides an unmatchable source of planetary properties and make
possible for the first time to access to an accurate ensemble of parameters such as radii or semi-major axis.
Multi-band observations of a TEP constrain much more the physical properties of the system. Parameters such as the inclination are independent of wavelength and can be determined much better if transits
at different passbands are observed. In addition, these observations also serve as a first-order broad-band
transmission spectrum, which can be used to search for the presence of strong absorbers. The measured
planetary radius is wavelength-dependent and measurements of its changes are indication of possible spectral variations. I will summarize the analysis and results of a multi-band observing campaign to characterize
the hot jupiters Wasp-44b, Wasp-5b, and Wasp-46b. These observations were carried out at the Observatorio
do Pico dos Dias (OPD/LNA), in Brazil. This study includes the first transit follow-up characterization of the
planet Wasp-46b.
B
1
2
3
[email protected]
Instituto de Astronomı́a, Universidad Católica del Norte
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas IAG/USP
Instituto Nacional de Pesquisas Espaciais/MCTI
27
Planetary Systems
Short Talks
PS -1
Creep tides. A new model to study the tidal evolution of close-in satellites and
exoplanets
Ferraz-Mello, S.B1
We present a new reophysical theory of the dynamical tides of celestial bodies in which the body tends always
to creep towards the equilibrium (inviscid) by the only action of the gravitational forces acting on it (selfgravitation and tidal potential) with a rate inversely proportional to its viscosity. The adopted creep law is
Newtonian linear) and at every instant the stress is assumed proportional to the distance to the equilibrium.
This leads to a non-homogeneous ordinary differential equation that determines the distortion due to the
tidal perturbation. In this approach the dissipation is inversely proportional to ( +
1) ( is the tide
frequency in units of a relaxation factor inversely proportional to the viscosity). In the inviscid limit, the
dissipation is roughly proportional to the frequency (as in standard theories), but when the viscosity is high
and the relaxation factor much smaller than the tide frequency the dissipation decreases almost linearly with
the frequency. The theory is applied to several Solar System and extrasolar bodies and values of the relaxation
factor are derived for these bodies. A numerical approach allowed us to overcome the cumbersome algebraic
manipulations involved in applications to more complex problems and to introduce the perturbations by a
third body. The results for the tidal terms of the physical libration of the Moon have been compared to the
values determined from the Lunar Laser Ranging measurements. The comparison of the predictions of the
theory to observations serves to validate the theory and also to indicate possible future improvements.
B
1
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas
28
Short Talks
Planetary Systems
PS -1
Stellar Occultations by Transneptunian and Centaurs Objects: results from more than
10 observed events
Braga-Ribas, F.B1 ; Vieira-Martins, R.1 ; Assafin, M.2 ; Camargo, J. I. B.1 ; Sicardy, B.3 ; Ortiz, J. L.4
Transneptunian objects (TNOs) and Centaurs are small fossils of the Solar System orbiting beyond Saturn.
Over 1200 of them have been found since 1992, and among them we find dwarf-planets such as Pluto, Makemake and Eris. Their origin, dynamical evolution and collisional history are linked to the formation of the
Solar System. Having information about their size and mass distribution, surface and internal structure
(albedo, shape and density) can help the understanding of the dynamical evolution of our system.
We use the stellar occultation technique which consists in observing a star while the object transit in
front of it. The precise duration of the event, observed from several different sites, allows to deduce their
size and shape with kilometric accuracy. If the object has an atmosphere (as Pluto for example), the light of
the star is attenuated during its ingress and egress behind the body, so we can determine its pressure down
to the nanobar level, or put a limit to its presence. Our group has developed a long-term prediction process
which consists of observing the sky path of selected objects, constructing an astrometric star catalogue used
to predict these events.
This work allowed us to detect several occultations and derive interesting results. For instance, we learned
that Eris, known as the biggest TNO, has the same size as Pluto within the error bars, but a very high albedo,
probably due to a condensed atmosphere. Makemake, the third biggest known TNO, has no global atmosphere and a high albedo. Quaoar has a diameter greater than 1100 km, a density of 2.0 ± 0.5 g cm3 , and a
low albedo. Varuna and 2003 AZ84 , other big objects, are very elongated. These results, among others, will be
detailed, and their impact to our knowledge about these far objects, will be discussed.
By the time of this writing thirteen events were already observed by our group, involving nine different
objects, in an international consortium between the Observatório Nacional / BR - Paris-Meudon Observatory / FR - Instituto de Astrofı́sica de Andalucı́a / ES.
B
1
2
3
4
[email protected]
Observatório Nacional / MCTI, Rio de Janeiro, Brazil
Observatório do Valongo/UFRJ, Rio de Janeiro, Brazil
Observatoire de Paris - Meudon / LESIA, Meudon, France
Instituto de Astrofı́sica de Andalucı́a, CSIC, Spain
29
Planetary Systems
Short Talks
PS -1
Imaging polarimetry of the potentially planet-forming circumstellar disk HD 142527.
The NaCo view
Cánovas, H.B1,9 ; Ménard, F.2,6,9 ; Hales, A.3,4,9 ; Jordán, A.5,9 ; Schreiber, M. R.1,9 ; Casassus, S.6,9 ; Gledhill, T. M.7 ; Pinte, C.8
HD 142527 is a unique system in terms of planet formation. Its high accretion rate combined with its huge
inner gap and short age make of it an ideal candidate for harboring forming planets. ALMA cycle-0 observations revealed gap crossing gas streams and showed that the millimeter-sized dust particles are distributed
in a horse-shoe shape. Here I present our recent NIR imaging polarimetry results of HD 142527 obtained
with NaCo/VLT. By means of polarimetry, we remove most of the stellar light, directly imaging the disk’s inner regions. Our observations allow us to constrain the dust properties (size, composition and porosity) on
the surface of the the outer disk. We also detect two regions of the disk with low emission (”nulls”) both
in polarized and unpolarized light. Intriguingly, one of these nulls is azimuthally coincident with the maximum of the horse-shoe shape detected by ALMA. We discuss the possible link between these two (different?)
features.
B
1
2
3
4
5
6
7
8
9
[email protected]
Departamento de Fı́sica y Astronomı́a, Universidad de Valparaı́so, Valparaı́so, Chile
UMI-FCA, CNRS / INSU France (UMI 3386)
Atacama Large Millimeter/Submillimeter Array, Joint ALMA Observatory, Alonso de Córdova 3107, Vitacura 763-0355, Santiago - Chile
National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, Virginia, 22903-2475, United States
Instituto de Astrofı́sica, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago, Chile
Departamento de Astronomı́a, Universidad de Chile, Casilla 36-D, Santiago, Chile
Science and Technology Research Institute, University of Hertfordshire, College Lane, Hatfield AL10 9AB, UK
UJF-Grenoble 1 / CNRS-INSU, Institut de Planétologie et d’Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble, F-38041, France
Millenium Nucleus “Protoplanetary Disks in ALMA Early Science”, Universidad de Chile, Casilla 36-D,Santiago, Chile
30
Short Talks
Planetary Systems
PS -1
The Janus-Epimetheus Ring
B1
Winter, O. C.
; Pinho, A.1 ; Sfair, R.1 ; Mourao, D. C.1 ; Foryta, D.2 ; Giuliatti Winter, S. M.1
The known planetary ring systems of Saturn, Jupiter, Uranus and Neptune present a wide range of peculiar
cases. However, a different from all of them has been found sharing its trajectory with Janus and Epimetheus,
co-orbital satellites of Saturn. In the present work we show that, behaving like a firefly, this ring can only be
seen from time to time, when the Cassini spacecraft, the ring and the Sun are in a particular geometric configuration. Otherwise, it “remains in the dark”, not being visible by the spacecraft camera. Another interesting
feature of the Janus-Epimetheus ring (J-E ring) is that all its particles are removed from the ring within the
shortest lifetime ever found among the planetary rings. The large particles (> 8 micrometers) have a lifetime of at most a few years, being removed by collisions with one of the co-orbital moons, while the small
particles (< 8 micrometers) show even shorter lifetimes (a few tens of days), being removed by encounters
with the F ring. So, the J-E ring needs to be constantly replenished. Using Janus and Epimetheus as targets
and considering the flux of micrometeorites that reaches the J-E ring region, we developed a detailed physical model that matches very well the data of the J-E ring extracted from Cassini images. We show that the
existence of the J-E ring is due to the constant supply of material extracted from the co-orbital moons by
collisions with micrometeorites, and the generated size distribution of particles selects the light scattering
regime responsible for the “firefly” behaviour of this ring.
B
1
2
[email protected]
Grupo de Dinamica Orbital e Planetologia - UNESP - Guaratingueta - SP - Brazil
Departamento de Fisica - UFPR - Curitiba - PR - Brazil
31
Planetary Systems
Short Talks
PS -2
Young Brown Dwarfs as Giant Exoplanet Analogs
Faherty, J. K.B1,2,3 ; Rice, E.2,4 ; Cruz, K.2,5
Young brown dwarfs and directly-imaged exoplanets have enticingly similar photometric and spectroscopic
characteristics, indicating that their cool, low gravity atmospheres should be studied in concert. We have
identified, confirmed, and characterized several new young M and L type brown dwarfs (see Faherty et al.
2013) and compared them to directly-imaged planetarymass companions and exoplanets like 2MASS 1207b
and HR8799b. Similarities between the peculiar shaped H band and location on near-IR color magnitude
diagrams provide important clues about how to extract physical properties of planets from current brown
dwarf observations. In this talk I will present newly found systems and describe our comparative browndwarf exoplanet studies.
B
1
2
3
4
5
[email protected]
Universidad de Chile
American Museum of Natural History
Carnegie Department of Terrestrial Magnetism
College of Staten Island
Hunter College
32
Short Talks
Planetary Systems
PS -2
Precise stellar occultation predictions for 39 selected TNOs/Centaurs
Camargo, J. I. B.B1 ; Assafin, M.2 ; Vieira-Martins, R.1 ; Sicardy, B.3 ; Braga-Ribas, F.1 ; Desmars, J.1 ; Benedetti-Rossi, G.1 ;
Dias-Oliveira, A.1,3 ; Andrei, A. H.1 ; da Silva Neto, D. N.4
Trans-Neptunian objects (TNOs) are Solar System bodies located in the range within 30 100 AU from the
Sun. They are also relics, relatively unaltered, of the proto-planetary disk from which Solar System planets
emerged. Therefore, these are key objects to help us better understand the history and evolution of the outer
Solar System.
Centaurs are a population of objects orbiting closer to the Sun than the TNOs and Neptune. They can be
interpreted as small size representatives of the same primitive parent population of TNOs, filling up the gap
of small TNOs that cannot be observed with current telescope facilities. Currently, about 200 Centaurs are
known. One of the ways to study these bodies, TNOs and Centaurs, is given by the analysis of a light curve as
obtained when they occult a star.
Stellar occultations are the only ground-based way to derive their sizes with kilometric accuracy and detect putative atmospheres as tenous as few nanobars. These events, rare in many cases and that naturally
encourage international collaborations, always require a huge observational and computational work to predict where and when on the Earth they can be observed. Different sets of observations are used to determine
the positions of TNOs/Centaurs and of the stellar content around their paths on the sky. An initial accuracy
of 000 .05 is obtained to all positions which must be then refined to 000 .02 as the possible event approaches.
As a continuation of previous works, where predictions of stellar occultations by Pluto (plus Charon,
Nix and Hydra) and 10 other large TNOs (Assafin et al. 2010, 2012) were made, we have just concluded the
preparation of predictions for a set of 39 selected TNOs and Centaurs for the period 2012.5 to the end of 2014.
The necessary observational data was acquired during 4 consecutive semesters, from 2011 to 2013, at La Silla
with the ESO/MPG 2.2m telescope equipped with its Wide Field Imager (WFI). It is relevant to mention that
these works have predicted almost all of the stellar occultations by TNOs observed so far, exception made
for Pluto.
Here, we present the whole process involved in determining the predictions as well as some important
problems and possible solutions, from observations to ephemeris corrections. We also present some selected predictions and light curves along with expectations for the near future of this work.
B
1
2
3
4
[email protected]
Observatório Nacional / MCTI
Observatório do Valongo / UFRJ
Observatoire de Paris-Meudon - França
Universidade Estadual da Zona Oeste / RJ
33
Planetary Systems
Short Talks
PS -2
Large Semimajor Axis Centaurs: where do they come from?
Gomes, R. S.B1 ; Soares, J. S.1 ; Brasser, R.2
Centaurs are Solar System objects in unstable orbits whose perihelia are in the realm of the major planets.
Some of these Centaurs have large semimajor axis (Laces) with their aphelia beyond 2000 AU. Small semimajor axis Centaurs are usually believed to originate in the scattered disk, but Laces would have as its most
likely origin the Oort Cloud. We argue however that the Oort Cloud could not produce as many Laces as
are estimated through the number of those already observed. In this way, we propose that a still undiscovered planetary mass solar companion could be enhancing the production of Laces thus accounting for the
current number of observed Laces.
B
1
2
[email protected]
Observatório Nacional, Rio de Janeiro, Brasil
Institute for Astronomy and Astrophysics, Academia Sinica, Taipei 106, Taiwan
34
Short Talks
Planetary Systems
PS -2
Atlas of the three body resonances in the Solar System
Gallardo, T.B1
Three body resonances (TBRs) between a massless particle with an arbitrary orbit and two planets P1 and P2
in circular coplanar orbits occur when the critical angle
= k0
0
+ k1
1
+ k2
2
(k0 + k1 + k2 )$0 being ki
integers is oscillating over time. The approximate localization in semimajor axis of the TBRs taking arbitrary
pairs of planets is very simple, specially if we ignore the secular motion of the perihelion and nodes of the
perturbing planets. When these slow secular motions are taken into account each of the nominal three body
resonances split in a family of resonances all them very near the nominal one. The challenge is to obtain the
width, strength or whatever that give us the dynamical relevance of these TBRs. We propose an algorithm
to numerically estimate the strength of arbitrary TBRs between two planets in circular coplanar orbits and a
massless particle in an arbitrary orbit. This algorithm allowed us to obtain an atlas of the TBRs in the Solar
System showing where are located and how strong are thousands of TBRs involving all the planets from 0 to
1000 au. Relevant results for the population of asteroids and transneptunian objects will be presented.
B
1
[email protected]
Facultad de Ciencias, Universidad de la República, Uruguay
35
Planetary Systems
Short Talks
PS -3
Detectability of Habitable Planets around Very Low-Mass Stars
Martioli, E.B1 ; Martı́n, E. L.2 ; Cabrera, J.3 ; Solano, E.2 ; Tata, R.4
We present observations of 18 very low-mass stars with Kepler light curves available in the public archive,
where we performed a search for transits and characterized the photometric variability to estimate the effects of stellar activity in the detectability of habitable planets around stars at the cool end of the stellar mass
distribution. We obtained low-resolution red optical spectra and found the spectral types of these targets to
lie in the range dM4.5–dM8.5, implying spectrophotometric distances from 17 pc to 80 pc. We find that the
size of the planets detectable by Kepler around these small stars typically lie in the range 1 to 5 Earth radii
within the habitable regions (P10 days). For 11 of these objects reliable photometric periods shorter than 7
days are derived, and are interpreted as rotational modulation of magnetic cool spots. For 3 objects we find
possible photometric periods longer than 50 days that require confirmation. H-alpha emission measurements and flare rates are used as a proxies for chromospheric activity and transversal velocities are used as
an indicator of dynamical ages. We discuss the relationship between age, magnetic activity and rotation in
fully convective stars, and the detectability of planets around them. We show that Super-Earth planets with
sizes around 2 Earth radii are detectable with Kepler around about half of the stars in our sample, independently from their level of chromospheric activity.
B
1
2
3
4
[email protected]
Laboratório Nacional de Astrofı́sica (LNA/MCTI)
Centro de Astrobiologı́a (INTA-CSIC)
Institute of Planetary Research, German Aerospace Center
Instituto de Astrofı́sica de Canarias
36
Short Talks
Planetary Systems
PS -3
Tidal, thermal and magnetic evolution of terrestrial exoplanets in the habitable zone of
dwarf stars
P. Cuartas-RestrepoB1 ; M. Melita2 ; J. Zuluaga1 ; J. Hoyos3 ; M. Sucerquia1
The rotation and thermal evolution of a planet plays a main role in the planetary magnetic field evolution.
The rotation period determines properties like the regime of the planetary dynamo and its intensity. This is
crucial for a planet to keep its reservoir of volatile material like water, protected against the erosive action of
the stellar wind and cosmic rays. Planets orbiting dwarf stars are tidally afected by their host, this detemines
the final rotation period (resonance) or the tidal locking of the planet, especially during the very first Myr.
At the same time this first period of the planet history is the most afected by the magnetic activity of the
host star. We calculate the rotation and tidal evolution of planets and combine this with a thermal evolution model to know how this very first stages of the planetary evolution finish with an stable and protective
planetary magnetic field or with an unprotected planet.
B
1
2
3
[email protected]
Instituto de Fı́sica - FCEN, Universidad de Antioquia, Medellı́n, Colombia
Instituto de Astronomı́a y Fı́sica del Espacio - IAFE, Buenos Aires, Argentina
Departamento de Ciencias Básicas, Universidad de Medellı́n, Medellı́n, Colombia
37
Planetary Systems
Short Talks
PS -3
Mapping the early distribution of volatiles in the Main Belt with the JPAS/J-PLUS
photometric survey
J. M. CarvanoB1 ; M. De Prá1 ; D. Lazzaro1 ; F. Roig1 ; A. Alvarez-Candal1 ; T. Mothé-Diniz2
The JPAS/J-PLUS is a joint Spanish-Brazilian project that aims to map an area of the sky of 8000 square
degrees, in order to measure, with unprecedented accuracy, the redshifts of a large sample of extragalactic
objects up magnitude 23. It involves the installation of two telescopes on the Javalambre Mountains, in
Spain. The T250 telescope will have an aperture of 250cm and will be equipped with a camera with a 3 square
degree field of view and will use a set of 56 filters (54 narrow band + 2 wide band) covering the 0.3-1.0 micron
range, while the T80 telescope (presently on commissioning phase) will have a camera with 2 square degree
field of view and will use a set of 12 narrow and intermediate band filters covering the same wavelength
range. During its execution, the surveys will also observe a large number of minor Solar System bodies. For
those objects, the differential of JPAS/J-PLUS with respect to other large photometric survey is the number
and position of the filters used, which will allow a better identification of some taxonomic classes that are
not well defined only with SDSS-like filter systems. In particular, the JPAS/J-PLUS data set will allow a robust
identification of the 0.7 micron water alteration band that characterize the Ch class in Bus taxonomy. Thus,
with JPAS/J-PLUS it will be possible to map the occurrence of water alteration in the present Solar System,
which in turn will allow us to put further constraints of the presence of volatiles and of heating processes in
the early Solar System.
B
1
2
[email protected]
Coordenadoria de Astronomia e Astrofı́sica, Observatório Nacional - MCTI
Observatório do Valongo, UFRJ
38
Short Talks
Planetary Systems
PS -3
A dynamical mechanism to produce high-inclinations TNOs
Brasil, P. I. O.B1,2 ; Gomes, R. S.2,3 ; Nesvorný, D.2
We discuss the dynamical formation of small Solar System objects beyond Neptune. The discovery of the
first trans-Neptunian object (TNO)
except for Pluto and Charon
is relatively recent (1992QB1 ). Many
unpredicted dynamical and physical features not predicted in past theoretical models and are now showing
up. Among them, we note the existence of many high-inclined orbits with respect to the eclipitc plane (where
all Solar System bodies supposedly have formed).
The aim of this work is to show a dynamical pathway from the primordial planetesimal disk to high inclinations orbits in the trans-Neptunian region. The main mechanism requires that scattered planetesimals
are captured into some exterior mean motion resonance (MMR) with Neptune and then be trapped into the
Kozai resonance as well. After that, some planetesimals may access a resonance hibernating mode in which
the planesimal is barely locked in resonance. We show that only a few percent of all scattered planetesimals would access the hibernating mode. But, once this mechanism is active, ⇠ 100% of the particles would
escape both resonances while Neptune is in its final migration stage (after the LHB phase).
Our results could explain at least a portion (up to 80%) of the classical hot population, defined by a2:3 <
a < a1:2 , i > 5o , and q > 36au. Previous results indicate that this mechanism is the most likely to form the
detached objects close to MMR with Neptune as, for example, 2004XR190 (Gomes, 2011, Icarus 215, 661). We
have determined the most probable regions, in the orbital elements space (a, e, i), where detached objects
would form close to 2:5 and 1:3 MMRs (Brasil, Gomes & Soares, 2013 - submitted to A&A).
B
1
2
3
pedro [email protected]
Instituto Nacional de Pesquisas Espaciais, Divisão de Mecânica Espacial e Controle - INPE/DMC
Southwest Research Institute, Departments of Space Studies and Space Operations - SwRI/DSSSO
Observatório Nacional, Grupo de Pesquisa em Astromomia - ON/GPA
39
40
Stars & Stellar Systems
SSS -1
A study of the recent chemical evolution of the Large Magellanic Cloud
Palma, T.B1,2 ; Clariá, J. J.1,2 ; Geisler, D.3 ; Ahumada, A. V.1,2
We present the results of a study of the Large Magellanic Cloud (LMC) chemical evolution during the last
2.2 Gyr. This study was based on Washington photometric observations of LMC’s star clusters carried out
with the Cerro Tololo Inter-American Observatory (CTIO) 4 m telescope. As tracers of the LMC’s chemical enrichment, we used 83 star clusters projected both on the bar and in the inner and outer LMC disc,
more than half of which have not been previously studied. We determine size, reddening, deprojected distance, age and metallicity of the observed star clusters. We show that the most metal-poor clusters are distributed throughout the entire disc while most metal-rich clusters are mainly located in the inner disc. We
find that the youngest clusters tend to be located in the inner disc whereas intermediate-age clusters are
mainly found at larger deprojected Galactocentric distances. These trends are maintained when the sample
is complemented with clusters observed by other authors using the same technique. These results appear
to strengthen the idea of the absence of a radial metallicity gradient in the LMC for metal-poor clusters. The
resulting age-metallicity relationship appears to be unrelated to what LMC region is considered.
B
1
2
3
[email protected]
Observatorio Astronómico, Universidad Nacional de Córdoba, Argentina
CONICET
Departamento de Astronomı́a, Universidad de Concepción, Chile
41
Stars & Stellar Systems
Short Talks
SSS -1
Star clusters in an infalling galaxy
Mora M. D.B1 ; Chanamé J.1 ; Puzia T.1
Star clusters are among the most common stellar systems in the universe. Their formation occurs as part
of a hierarchical process where large interstellar regions fragment into giant molecular clouds and cloud
cores (e.g. Elmegreen 2011). These fragments are highly sub-structured, containing dense clumps and filaments showing a typical fractal dimension (e.g. Scheepmaker et al. 2009a; Sanchez & Alfaro 2008) where
cluster-cluster interactions occurs and may lead to star-cluster disruption or star-cluster merging (Kroupa
1998; Fellhauer & Kroupa 2005). In this work we present the discovery of several young star clusters and star
cluster complexes in NGC 1427A, a dwarf irregular galaxy that is likely infalling toward the center of the Fornax galaxy cluster for the first time at supersonic speed (Chanamé et al. 2000). Its apparent morphological
distortion and star clusters lining up within the bow-shock region make us to believe that this star formation
activity is triggered by the passage through the hot intra cluster medium of the Fornax cluster.
B
1
[email protected]
Pontificia Universidad Católica Chile
42
Short Talks
Stars & Stellar Systems
SSS -1
Planetary nebulae near the Galactic centre: chemical abundances
Cavichia, O.B1 ; Costa, R. D. D.1 ; Maciel, W. J.1 ; Molla, M.3
Planetary nebulae (PNe) are the offspring of stars within a large mass interval (0.8
8 M ). PNe consti-
tute an important tool to study the chemical evolution of the Milky Way and other galaxies, probing the
nucleosynthesis processes, abundance gradients and the chemical enrichment of the interstellar medium.
However, the presently available chemical composition studies are strongly biased, since they were focused
on brighter objects, predominantly located in Galactic regions of low interstellar reddening. In this work,
we report physical parameters and abundances derived for a sample of high extinction PNe located in the
Galactic bulge, near the Galactic centre, based on low dispersion spectroscopy secured at the SOAR telescope
using the Goodman spectrograph. The new data allow us to extend our database including older, weaker objects that are at the faint end of the planetary nebula luminosity function (PNLF). The results show that the
abundances of our sample are similar to those from other regions of the bulge. Nevertheless, the average
abundances of the galactic bulge do not follow the observed trend of the radial abundance gradient in the
disk. We propose a chemical evolution model for the Galactic bulge to explain the observed data, adopting a
scenario where the bulge is formed in a single collapse timescale of 2 Gyr, which is longer than other chemical evolution models predict. There is no need to invoke a second infall episode, as recently suggested by
other authors to explain the observed bulge metallicity distribution.
B
1
2
[email protected]
Universidade de São Paulo
Dept. of Basic Research - CIEMAT
43
Stars & Stellar Systems
Short Talks
SSS -1
New axion bounds from the white dwarf luminosity function
Melendez, B. E.B1,2 ; Miller Bertolami, M. M.1,2,3
It has been shown that the shape of the luminosity function of white dwarfs (WDLF) can be a powerful tool
in order to check the possible existence of DFSZ-axions, a proposed but not yet detected type of weakly
interacting particle. In this research we show that the feedback of the axion emission into the neutrino
emission cannot be neglected at high luminosities (MBol  8), and that the axion emission need to be
incorporated in a self-consistent way into the evolution of the white dwarfs when dealing with axion masses
larger than ma cos2
5meV.
We have performed a
2
-test in order to have a quantitative measure of the agreement between the
theoretical WDLF -computed under assumptions of different axion masses- on the one hand and the observed WDLF on the other. Our results indicate that axion masses larger than ma cos2
10meV can be
rejected at more than a 99.9% confidence level and that the existence or non-existence of axions with masses
ma cos2
 5meV cannot be concluded at any significant confidence level with the current knowledge of
the WDLF. Our results also confirm the disagreement between the observed WDLF and the cooling speed by
asteroseismological tools on G117-B15A.
B
1
2
3
[email protected]
Facultad de Ciencias Astronómicas y Geofı́sicas de La Plata, La Plata, Argentina
Instituto de Astrofı́sica de La Plata (IALP), UNLP-CONICET, La Plata, Argentina
Max-Planck-Institut fur Astrophysick, Garching, Germany
44
Short Talks
Stars & Stellar Systems
SSS -2
Asteroseismology of massive pulsating DA white dwarf stars with fully evolutionary
models
A. D. RomeroB1 ; S. O. Kepler1 ; A. H. Córsico2 ; L. G. Althaus2 ; L. Fraga3
In this work we performed the first asteroseismological study for 42 massive DA white dwarf stars, or ZZ
Ceti, based on detailed and fully evolutionary models representative of these stars. Our DA white dwarf
models, cover a wide range of stellar masses, effective temperatures, and envelope thicknesses, are the result
of fully evolutionary computations that take into account the complete history of the progenitor stars from
the ZAMS. In addition, these models are characterized by a detailed and consistent chemical inner profile for
the core and the envelope, which is crucial in white dwarf asteroseismology. Our sample comprise all the ZZ
Ceti stars with spectroscopic stellar masses between 0.72 and 1.05M know to date. The asteroseismological
analysis of a set of 42 stars gives the possibility to study the ensemble properties of the massive pulsating
white dwarf stars with carbon oxygen cores, in particular the thickness of the hydrogen envelope and the
stellar mass.
B
[email protected]
Departamento de Astronomia, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500 Porto Alegre 91501-970, RS,
Brazil
2 Facultad de Ciencias Astronómicas y Geofı́sicas, Universidad Nacional de La Plata, Paseo del Bosque s/n, (1900) La Plata, Argentina,
Instituto de Astrofı́sica La Plata, CONICET-UNLP, Argentina
3 Southern Observatory for Astrophysical Research, Casilla 603, La Serena, Chile, Laboratório Nacional de Astrofı́sica – LNA/MCTI, R.
Estados Unidos, 154, Itajubá, MG, CEP: 37504-364, Brazil
1
45
Stars & Stellar Systems
Short Talks
SSS -2
MLS110213:022733+130617: A new eclipsing polar above the period gap
Silva, K. M. G.B1 ; Rodrigues, C. V.1 ; Oliveira, A. S.2 ; Almeida, L. A.1 ; Cieslinski, D.1 ; Costa, J. E. R.1
Polars are magnetic cataclysmic variables (CVs): short period binaries in which a low-mass main-sequence
star transfers matter to a magnetic white dwarf via an accretion column. A stand-off shock is formed near
the white-dwarf surface, followed by a hot post-shock region that cools down by cyclotron radiation mainly
in optical and infrared ranges. Over a 135 polars and polar candidates were identified so far: ⇠ 26% have
periods over the period gap ( P > 3h) and only 6 of these systems are eclipsing.
We have obtained photometry and polarimetry (OPD) and spectroscopy (SOAR) data of MLS110213:
022733+130617 which is one of the polar candidates identified and monitored by the Catalina Sky Survey
(CSS). After analyzed all the available data (OPD,SOAR,CSS) covering the last 7 years, we confirm the system
as a new eclipsing polar.
The long term observations obtained by CSS shows the system in two distinct brightness state, 1.5 mag
apart. This kind of variation in polars are explained as variations in the mass rate accretion. A deep eclipse
is observed with a decrease of 3 (1.5) mag in high (low) brightness state, indicating that system has a high
inclination. From the mid-eclipse of the photometric data we estimated an orbital period of 3.787 hours
which is in the above the period gap with only three other systems showing longer periods.
In the high state of brightness, the light curve outside the eclipse is almost flat, while in the low state a
strong modulation is observed, with a phase maximum 0.175. The polarimetric data is from high state of
brightness. The system presents circular polarization varying in the range -3 to 15% in R-band, with a phase
maximum 0.175, consistent with low state maximum, which confirms that this component is mainly due to
cyclotron emission from the accretion column. The polarization does not have a standstill at zero, and there
are phases when the signal changes, indicating a region always visible, but observed from the backside in
some fases.
A spectrum in the energy range 4500-7000 Å was obtained in the phase interval 0.7-0.88 which shows a flat
continuum and strong emission-lines. There’s no clear evidence of the secondary star presence, however it
shows the typical characteristic high ionized optically thick regions: i) Inverse Balmer series decrement (H↵
< H < H ) and ii) intense HeII 4686 are present.
B
1
2
[email protected]
Instituto Nacional de Pesquisas Espaciais
Universidade do Vale do Paraı́ba
46
Short Talks
Stars & Stellar Systems
SSS -2
Symbiotic stars in X-rays and UV
Luna, G. J. M.B1 ; Sokoloski, J. L.2 ; Mukai, K.3 ; Nelson, T.4 ; Nuñez, N. E.5
Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to
be mainly a soft X-ray population. I will describe the detection with the Swift/XRT of 14 white dwarf symbiotics that were not previously known to be X-ray sources. The 14 new X-ray detections were the result of
a survey of more than 50 symbiotic stars using Swift fill-in programs during three years. Their X-ray spectra
are consistent with thermal emission and fall naturally into three distinct groups. The first group contains
those sources with a single, highly absorbed hard component, which we identify as probably coming from
an accretion-disk boundary layer. The second group is composed of those sources with a single, soft Xray spectral component, which likely arises in a region where low-velocity shocks produce X-ray emission,
i.e. a colliding-wind region. The third group consists of those sources with both hard and soft X-ray spectral components. Simultaneous Swift/UVOT data allowed us to find that unlike in the optical, where rapid,
stochastic brightness variations from the accretion disk typically are not seen, detectable UV flickering is a
common property of symbiotic stars. Supporting our physical interpretation of the two X-ray spectral components, the UV photometry shows that symbiotic stars with harder X-ray emission tend to have stronger
UV flickering, which is usually associated with accretion through a disk.
B
1
2
3
4
5
[email protected]
Instituto de Astronomia y Fı́sica del Espacio, CONICET
Columbia University
NASA/GSFC & USRA
University of Minnesota
Instituto de Ciencias Astronómicas, de la Tierra y del Espacio
47
Stars & Stellar Systems
Short Talks
SSS -2
Time-lapse and flickering mapping of accretion discs: measuring the disc viscosity
parameter
Raymundo BaptistaB1
Flickering is the intrinsic brightness fluctuation of 0.01-1 mag on timescales of seconds to dozens of minutes
that is seen in light curves of T Tau stars, mass-exchanging binaries and active galactic nuclei. It is considered
a basic signature of accretion, and may be used to probe the anomalous viscosity that powers accretion
discs. Maximum-entropy eclipse mapping techniques are key to the study of flickering and accretion disc
viscosity in mass-exchanging binaries. By measuring the (viscous) timescale with which the disc responds
to changes in mass input rate, one might infer the average disc viscosity parameter ↵ (time-lapse mapping).
Moreover, by combining a large ensemble of lightcurves one can separately measure the low- and highfrequency flickering amplitude as a function of binary phase and derive maps of their surface brightness
distributions from their eclipse shapes (flickering mapping).
Flickering mapping of quiescent dwarf novae reveal that low-frequency flickering is associated to turbulence in the mass-transfer process, whereas high-frequency flickering arises in the accretion disc. Interestingly, if the disc-related flickering is caused by magneto-hydrodynamic turbulence in the disc’s atmosphere,
its relative amplitude yields a direct measure of the ↵-viscosity parameter. The three dwarf novae mapped
with this technique so far show high viscosity discs in quiescence (↵ ' 0.1
0.2). This is at odds with the
thermal-viscous disc instability model to explain dwarf nova outbursts, which predicts that their discs switch
between a cool, low-viscosity regime (↵ ⇠ 10
outburst.
B
1
2
) in quiescence to a hot, high-viscosity regime (↵ ⇠ 10
[email protected]
Universidade Federal de Santa Catarina, Brazil
48
1
) in
Short Talks
Stars & Stellar Systems
SSS -3
Two rings but no fellowship: LoTr 1 and its relation to planetary nebulae possessing
Barium central stars
Tyndall, A. A.B1,2 ; Jones, D.2 ; Boffin, H. M. J.2 ; Miszalski, B.3,4 ; Faedi, F.5 ; Lloyd, M.1 ; Lopez, J. A.6 ; Martell, S.7 ;
Pollacco, D.5 ; Santander Garcia, M.8
LoTr 1 is a planetary nebula thought to contain an intermediate-period binary central star system. The system shows the signature of a K-type, rapidly rotating giant, and most likely constitutes an accretion-induced
post-mass transfer system similar to other PNe such as LoTr 5, WeBo 1 and A70. Such systems represent
rare opportunities to further the investigation into the formation of Barium stars and intermediate period
post-AGB systems – a formation process still far from being understood. Here, we present the first detailed
analyses of both the central star system and the surrounding nebula of LoTr 1 using a combination of spectra
obtained with VLT-FORS2, AAT-UCLES and NTT-EMMI, as well as SuperWASP photometry.We confirm the
binary nature of the central star of LoTr 1 that consists of a K1 III giant and a hot white dwarf. The cool giant
does not present any sign of s-process enhancement but is shown to have a rotation period of 6.4 days, which
is a possible sign of mass accretion. Both LoTr 1 and A 70 also present broad double-peaked H↵ emission
lines, whose origin is still unclear. The nebula of LoTr 1 consists in two slightly elongated shells, with ages of
17 000 and 35 000 years, respectively, and with different orientations. As such, LoTr 1 present a very different
nebular morphology than A70 and WeBo 1, which may be an indication of difference in the mass transfer
episodes.
B
1
2
3
4
5
6
7
8
[email protected]
Jodrell Bank Centre for Astrophysics, UK
European Southern Observatory
South African Astronomical Observatory
South African Large Telescope
University of Warwick, UK
Instituto de Astronomia, Universidad Nacional Autonoma de Mexico
Australian Astronomical Observatory
Observatorio Astronómico National, Madrid
49
Stars & Stellar Systems
Short Talks
SSS -3
Search for Southern Galactic Be star candidates
B. E. SabogalB1 ; A. Garcı́a-Varela2 ; R. E. Mennickent2
We present the result of a search for Galactic Be star candidates within the miscellaneous ASAS-2 Catalogue
of Variable Stars. This search, performed using statistical, photometrical and morphological criteria, leads
us to find 691 new southern Be star candidates.
A comparison of photometric properties of these stars with those of Be star candidates in the Magellanic
Clouds suggests that outbursting stars are more scarce in our Galaxy than in the Magellanic Clouds. We do
not find stars showing clear high and low states similar to those detected in the Magellanic Clouds. Stars with
periodic or quasi-periodic variations are more abundant than outbursting stars. The amplitudes of outbursts
observed in our selected stars seem to confirm that the processes of mass ejection are less energetic in the
higher metallicity environment of the Galaxy.
B
1
2
[email protected]
Universidad de los Andes, Departamento de Fı́sica, Cra. 1E No. 18A-10, Edificio Ip, A.A. 4976, Bogotá, Colombia
Universidad de Concepción, Departamento de Astronomı́a, Casilla 160-C, Concepción, Chile
50
Short Talks
Stars & Stellar Systems
SSS -3
Viscous Disks in Be Stars
B1
Rimulo, L. R.
; Carciofi, A. C.1 ; Mota, B. C.1 ; Haubois, X.2 ; Rivinius, T.3
The fast-spinning Be stars offer a testbed for developing and testing astrophysical theories in their limit. For
the star proper, rapid rotation allows for studying the effects of rotation on the stellar evolution and structure.
Recent interferometric studies of the photosphere, for instance, allowed for measuring the gravity darkening
coefficient and the results present a challenge for current models. Be star phenomenology is strongly associated with their circumstellar disks. On one hand, the disk acts as a sink of angular momentum, and this fact
couples the disk with the evolution of the central object. On the other hand, the disk reprocesses starlight,
thereby modifying the emerging spectrum. In the past decade our understanding of these disks saw a major
leap forward; with the very high angular resolution that can be achieved with modern interferometers we
can now resolve the disk up to the immediate vicinity of the star, as well as determining the disk kinematical properties. Coupled with advancements in the physical modeling of these systems, these observations
allowed for establishing the viscous decretion disk model as the most viable scenario for disk formation and
evolution. In this model, material that is ejected with Keplerian or super-Keplerian speeds at the base of
the star and diffuses outwards by means of viscous forces. More recently, models became available for the
temporal evolution of these disks when subject to variable feeding rates. In this contribution we will discuss
how these dynamical disk models can be used for constraining fundamental disk parameters, such as the
alpha viscosity parameter, and we will report on an ongoing effort to model light curves of a large number of
stars.
B
1
2
3
[email protected]
Universidade de São Paulo, Brazil
Sydney Institute for Astronomy, Australia
ESO, Chile
51
Stars & Stellar Systems
Short Talks
SSS -3
The Be star Achernar and its circumstellar environement
Faes, D. M.B1,2 ; Carciofi, A. C.1 ; Domiciano de Souza, A.2
The circumstellar disks ejected by many rapidly rotating B stars (so-called Be stars) offer the rare opportunity
to study the structure and dynamics of gaseous disks at high spectral as well as angular resolution. Recent
works, largely based on optical long baseline interferometry, showed that Achernar (↵ Eridani, HD10144), the
brightest (V = 0.46 mag) and nearest (distance of 42.5 pc) Be star is a key target to a deeper understanding of
the physics of Be stars, because it displays most of features that characterizes the Be phenomenon: (i) Strong
rotational rate; (ii) Residual disk; (iii) Episodic mass ejections; (iv) Quasi-cyclic disk formation/dissipation;
(v) Polar wind; and (vi) Binarity. Here we present preliminary results for the recent history of Achernar. We
use a large set of observational data, such as AMBER spectro-interferometry and PIONIER interferometry
(VLTI/ESO), broad-band optical polarimetry (OPD/LNA) and multi-instruments spectroscopy. The radiative transfer code HDUST is used to analyze and interpret the observational dataset, aiming at obtaining a
realistic physical model of the circumstellar environment (disk and/or wind) in interaction with the stellar
photosphere. In particular, we analyse a preliminary inconsistency between Achernar’s 2009 AMBER and
2011 PIONIER interferometric data can be solved by the existence of a residual disk at the time of the first
observations; this residual disk is compared with the disk at the active phase of 2003 and, after seven years
of quiescense, the present active phase (2013). Lastly, a few words are given about the quasi-cyclic disk formation/dissipation and the binarity of the system.
B
1
2
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, Univ. of São Paulo
Observatoire de la Côte d’Azur, Univ. de Nice-Sophia Antipolis
52
Short Talks
Stars & Stellar Systems
SSS -4
A kinematic study of the Lupus star-forming region
Galli, P. A. B.B1 ; Bertout, C.2 ; Teixeira, R.1 ; Ducourant, C.3
To reliably determine the main physical parameters (mass and age) of young stellar objects a precise determination of the distance to individual stars is required. While the average distance to nearby star-forming
regions (< 300 pc) is often known, the distances to individual stars are usually unknown. Most pre-main sequence stars were neither observed by the Hipparcos satellite due to their magnitude nor have any trigonometric parallax measured from the ground due to their distance. In this context, we investigate the kinematic properties of the Lupus association of young stars with the primary objective of deriving individual
parallaxes for each group member. We identify those stars in the Lupus star-forming region that define the
co-moving association of young stars using our new and improved convergent point search method that
allows us to derive the precise position of the convergent point of a moving group and perform a membership analysis. We used published proper motion catalogs and searched the literature for radial velocities, which are needed to compute individual parallaxes via convergent point method. Our strategy also
made it possible to distinguish Lupus stars from the adjacent Upper Centaurus Lupus (UCL) subgroup of
the Scorpius-Centaurus association. Doing so, we derive individual parallaxes for 109 pre-main sequence
stars and discuss the properties of the various Lupus subgroups and pre-main sequence subclasses.
B
1
2
3
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, Universidade de São Paulo
Institut d’Astrophysique de Paris
Laboratoire d’Astrophysique de Bordeaux
53
Stars & Stellar Systems
Short Talks
SSS -4
A new library of theoretical stellar spectra for stellar population applications
Coelho, P.B1
Libraries of stellar spectra are one of the main ingredients of stellar population synthesis models. Theoretical libraries have been increasingly used in recent years to overcome limitations of empirical libraries,
in particular to explore parameter space (in temperatures, metalicities and abundance patterns) not well
covered by empirical libraries. In this talk, a new theoretical stellar library is presented. It consists of high
and low-resolution spectra which cover the parameter space required to the modelling of stellar populations
between 30 Myr and 14 Gyr, metalicities Z between 0.0017 and 0.0048, at both solar-scaled and ↵-enhanced
compositions. The characteristics of the library as well as comparisons to observations will be presented.
B
1
[email protected]
Universidade Cruzeiro do Sul
54
Short Talks
Stars & Stellar Systems
SSS -4
Improvement and analysis of the MILES library for stellar population modelling
Milone, A.B1 ; Sansom, A.2 ; Vazdekis, A.3,4 ; Sánchez-Blázquez, P.5 ; Allende Prieto, C.3,4 ; Falcón Barroso, J.3,4
The main limitation of current semi-empirical SSP models is the use of spectra from solar neighbourhood
stars, whose individual element abundances are not adequately considered. Typically only iron is taken as a
metallicity tracer, but the spectral energy distributions of stars and stellar systems considerably depend on
abundances of other metals (e.g. CNO group and ↵ elements). With the goal of assembling a new generation
of SSP models with variable ↵-enhancement assuming Mg as a proxy, we obtained magnesium abundances
with a precision of ⇠0.1 dex for nearly 80% of MILES stellar library (Mid-resolution Isaac Newton Telescope
Library of Empirical Spectra). The [↵/Fe] abundance ratio is known as a good temporal scale indicator for
the star formation since the ↵ and iron-group elements have distinct nucleosynthetic origins with different
time scales (respectively type II and type Ia supernovae). The higher this ratio is, the shorter the time scale
for stellar formation. The MILES library is being expanded by around 20% by including stars with known
parameters and Mg abundances. The transformation of their photospheric parameters to the MILES homogeneous system was carried out, but the calibration of [Mg/Fe] is still in progress. In parallel, C, N and
O abundances are also being compiled from published works for the library’s stars because these elements
play an important role on the blue spectral region. The main motivation is to improve the distribution of
stars over the parameter space (Tef f , log g, [Fe/H], [X/Fe]). We have also done careful comparisons of the
theoretical stellar predictions of the Lick System line-strength indices against the MILES data. These comparisons reveal that the behaviour of Fe-sensitive line indices is generally well reproduced by the theoretical
models, while other indices tend to show either some systematic offsets from the predicted relations or large
scatter about them. We have thus been analysing this set of compiled empirical data to test synthetic models
for stellar spectra used in population modelling.
B
1
2
3
4
5
[email protected]
Instituto Nacional de Pesquisas Espaciais (Brazil)
University of Central Lancashire (UK)
Instituto de Astrofı́sica de Canarias (Spain)
Universidad de La Laguna (Spain)
Universidad Autónoma de Madrid (Spain)
55
Stars & Stellar Systems
Short Talks
SSS -4
Estimating metallicities with isochrone fits done by global optimization to
photometric data of open clusters
Monteiro, H.B1 ; Oliveira, A. F.1 ; Dias, W. S.1 ; Caetano, T. C.1,2
The metallicity is a critical parameter that affects the correct determination fundamental characteristics
stellar cluster and has important implications in Galactic and Stellar evolution research. Fewer than 10%
of the 2174 currently catalog open clusters have their metallicity determined in the literature. In this work
we present a method for estimating the metallicity of open clusters via non-subjective isochrone fitting using the cross-entropy global optimization algorithm applied to UBV photometric data. The free parameters
distance, reddening, age, and metallicity simultaneously determined by the fitting method. The fitting procedure uses weights for the observational data based on the estimation of membership likelihood for each
star, which considers the observational magnitude limit, the density profile of stars as a function of radius
from the center of the cluster, and the density of stars in multi-dimensional magnitude space. We present
results of [Fe/H] for nine well-studied open clusters based on 15 distinct UBV data sets. The [Fe/H] values
obtained in the ten cases for which spectroscopic determinations were available in the literature agree, indicating that our method provides a good alternative to determining [Fe/H] by using an objective isochrone
fitting. Our results show that the typical precision is about 0.1 dex.
B
1
2
[email protected]
IFQ, UNIFEI
IAG, USP
56
Short Talks
Stars & Stellar Systems
SSS -4
Modeling photometric and spectroscopic data of HS 2231+2441: an HW Vir type system
with a brown dwarf companion
Almeida, L. A.B1,2 ; Daminelli, A.1 ; Rodrigues, C. V.2 ; Cieslinski, D.2
Stellar evolution is one of the most firmly established theories in modern Astrophysics. Precise values of fundamental parameters such as masses and radii of stars are crucial to test this theory to the level better than a
few percent. As eclipsing binary systems provide a straightforward method for measuring these parameters,
they play an important role in present observational efforts and theoretical developments. HW Vir type systems are an interesting class of eclipsing binaries with only a few known cases. These systems consist of a B
subdwarf (sdB) plus a M dwarf (dM) in a compact orbit (Porb ⇠ 0.1 days). In this study we present an analysis
of BVRC IC photometry and phase-resolved optical spectroscopy of the HW Vir type system HS 2231+2441.
From the spectroscopic data analysis, we derived the radial velocity semi-amplitude, K1 = 38.7 ± 0.8 km/s
of the sdB star. Modeling simultaneously the photometric and spectroscopic data with the Wilson-Devinney
code, we obtained the geometrical and physical parameters of HS 2231+2441. With orbital period Porb ⇠ 2.65
h, inclination i = 80.9 ± 0.6 and mass ratio q = M2 /M1 = 0.177 ± 0.06, the components of the system have,
M1 = 0.163 ± 0.06 M , M2 = 0.030 ± 0.006 M , R1 = 0.131 ± 0.005 R and R2 = 0.070 ± 0.005 R . We discuss
these results in the context of HW Vir systems and their evolution.
B
1
2
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas IAG/USP
Instituto Nacional de Pesquisas Espaciais/MCTI
57
Stars & Stellar Systems
Short Talks
SSS -5
a observations of three globular clusters: NGC 104 NGC 6205 NGC 7099
Paunzen, E.1,2 ; Illiev, I. K.2 ; Pintado, O. I.B3
Globular clusters are main astrophysical laboratories to test and modify evolutionary models. Thought to
be rather homogeneous in their local elemental distribution of members, new results suggest a wide variety
of chemical peculiarities. The preselection of apparent peculiar stars for a detailed spectroscopic analysis is
very important for globular cluster fields. Most regions are very dense and the target stars are, normally, very
faint. Photometry could be one way out of the dilemma since it is very efficient. Up to now, only observations
in the Johnson U BV (RI) and Strömgren uvby systems are able The tool of
a photometry is employed in
order to detect chemically peculiar Population II stars. This three filter narrow band system measures the
flux distribution in the region from 4900 to 5600Å in order to find any peculiarities around 5200Å. The first
a observations for 3 globular clusters: NGC 104, NGC 6205 and NGC 7099, give very promising results,
which will serve as a solid basis for follow-up observations including photometric as well as spectroscopic
studies.
B
1
2
3
[email protected]
Department of Theoretical Physics and Astrophysics, Masaryk University, Brno, Czech Republic
Rozhen National Astronomical Observatory, Institute of Astronomy of the Bulgarian Academy of Sciences, Smolyan, Bulgaria
Instituto Superior de Correlación Geológica, Tucumán, Argentina
58
Short Talks
Stars & Stellar Systems
SSS -5
Dynamical Properties of Blue Straggler Stars in Galactic Globular Clusters: NGC3201,
Omega Cen and NGC6218
Simunovic, M.B1,2 ; Puzia, T. H.1
Blue Straggler Stars (BSSs) have been shown to be promising indicators of the properties of their globular
clusters. Their internal dynamics could help constraint their formation mechanisms, which are likely related
to strong dynamical events occurring in the past, and therefore allowing for a direct test on the dynamical
state of their parent globular clusters. We present the first dynamical study of BSSs in three Galactic globular
clusters, NGC 3201, NGC 5139 (!Cen), and NGC 6218, based on medium-resolution spectroscopy (R ⇡ 10000)
obtained with the Inamori-Magellan Areal Camera & Spectrograph (IMACS) mounted at the 6.5 meter Baade
Magellan telescope. Our BSS candidate selection technique uses HST/ACS and ESO/WFI photometric data
out to > 4.5 rc . We use radial velocity measurements to discard non-members and achieve a success rate
of ⇠ 93%, which yields a sample of 116 confirmed BSSs. Using the penalized pixel fitting method (pPXF)
we measure the v sin(i) values of the sample BSSs and find a bimodal v sin(i) distribution function in each
globular cluster. About 90% of the BSS population in NGC 3201 and NGC 6218 exhibit values in the range
10 50 km s
1
, while ⇠ 80% of the BSSs in !Cen show v sin(i) values between 20 and 70 km s
BSSs in NGC 3201 and NGC 6218 which show v sin(i) > 50 km s
1
1
. We find that the
are all found in the central cluster regions,
inside a projected 2 rc , of their parent clusters. We find a similar result in !Cen for BSSs with v sin(i) > 70 km
s
1
which are all, except for two, concentrated inside 2 rc . In all globular clusters we find rapidly rotating BSSs
that have relatively high differential radial velocities which likely put them on hyperbolic orbits, suggestive of
strong dynamical interactions in the past. Based on stellar spin down and dynamical crossing timescales we
estimate that all the observed rapidly rotating BSSs are likely to form in their central cluster regions no longer
than ⇠ 300 Myr ago and may be subsequently ejected from their host globular clusters. Using dereddened
V
I colors of our photometric selection we show that blue BSSs in !Cen with (V
I)0 <
⇠ 0.25 mag show
a significantly increased v sin(i) dispersion compared with their red counterparts and all other BSSs in our
sample, therefore strongly implying that fast rotating BSSs are preferentially bluer, i.e. more massive. This
may indicate that this particular blue BSS population in !Cen was formed in an unique formation event
and/or through an unique mechanism.
B
1
2
[email protected]
Instituto de Astrofisica, Pontificia Universidad Catolica de Chile
Astronomisches Rechen-Institut, Heidelberg University
59
Stars & Stellar Systems
Short Talks
SSS -5
Metallicity effects on globular clusters: size and colour
Sippel, A. C.B1,2 ; Hurley, J. R.2
While it has been known for a long time that the sizes of globular clusters within our galaxy correlate to their
galactocentric distances, more recently it has also been found that blue, metal-poor clusters are on average
larger than red, metal-rich clusters in nearby galaxies. This has generated a debate on the origin of these
size differences. Using direct N-body simulations of globular clusters with different metallicities, we can
distinguish between structural and apparent (i.e. mass versus light) differences. We find that metallicity does
not affect the cluster structure, while metallicity alone can produces apparent size differences as observed.
In addition, we can trace the evolution of colour with time, which enables us to follow the evolution of a
dynamically evolved single stellar population.
B
1
2
[email protected]
ESO Santiago, Chile
Centre for Astrophysics and Supercomputing, Swinburne University, Melbourne Australia
60
Short Talks
Stars & Stellar Systems
SSS -5
R-Process Abundances in Metal-Poor Galactic Halo Stars
Siqueira-Mello, C.B1 ; Barbuy, B.1 ; Spite, M.2 ; Spite, F.2
The origin of the elements is a fundamental field in modern astrophysics, and the problem of the heavy elements has been gaining attention in recent decades. The site of the r-process production is not yet fully identified: the most likely sites are high-entropy neutrino-driven winds of neutron-rich matter in core-collapse
supernova, but alternative sites have been suggested, as the merging of two neutron stars or the merging
of a neutron star and a black hole. The origin of the lightest trans-Fe elements gallium through cadmium
adds another difficulty to this picture, since it has been attributed in varying degrees to several processes.
Observed abundances are the best clues to bring some light to this multiplicity of possible mechanisms, and
the extremely metal-poor (EMP) Galactic halo stars have a special role in this problem.
In this contribution we describe the results obtained with the EMP r-II star CS31082-001 in the frame of
the ESO Large Programme ”First Stars”. Most of the heavy elements are present in the ultraviolet (UV), and
for some of them only this spectral region has measurable lines. Using HST/STIS observations we provide
abundances for those elements, making this star the most complete r-II object studied, with a total of 37
detections of neutron-capture elements.
The analysis of the isotopic abundances is another approach to the problem. Example of that are the isotopic fraction measurements of barium in the well studied metal-poor halo subgiant star HD 140283, which
indicates a 100% contribution by the s-process in recent literature, in contradiction with the Truran’s theory since the metallicity of HD 140283 ([Fe/H]=-2.50±0.20) indicates presumably the absence of s-process
contribution.We present the solution of this twenty years long-standing problem with a genuine detection
of europium in HD 140283, in agreement with the prevision of a strong r- process contribution for the origin
of the heavy elements, showing that it is necessary to be careful with results obtained from isotopic analysis.
The study of r-I stars is a third interesting approach to the heavy elements problem. At least twice as
common as their extreme counterparts, the r-II stars, in this contribution we present the results obtained
from a sample of this class of stars, showing the place they have to help us solving this problem. Conclusions
and perspectives will be also presented.
B
1
2
[email protected]
IAG, Universidade de Sao Paulo
GEPI, Observatoire de Paris
61
Stars & Stellar Systems
Short Talks
SSS -6
Primera identificación astrométrica y espectrofotométrica de miembros de Bochum 7
Corti, M. A.B1,2 ; Orellana, R. B.1,3 ; Bosch, G. L.1,3
Una asociación OB es un grupo de estrellas jóvenes (edad  50 ⇥ 106 años) con tipos espectrales O y B, de
baja densidad, originado en una gran nube molecular. La importancia de su estudio radica en la interacción
entre la componente estelar y las varias fases gaseosas del medio interestelar, ya sea por creación de cáscaras
de HI o fenómenos globales como pueden ser el enriquecimiento de la galaxia por explosiones de supernovas. Se les adjudica también a estas estrellas de alta temperatura y luminosidad, ser buenas trazadoras de
los brazos espirales de la galaxia. Este trabajo tiene como objetivo continuar y profundizar el conocimiento
de la composición estelar de la asociación OB conocida como Bochum 7 (Moffat & Vogt, 1975, A&AS, 20, 85;
Lundstrom & Stenholm, 1984, A&AS, 58, 136; Sung et al. 1999, JKAS, 32, 109; Corti et al. 2007, A&A, 467,
137). La misma se encuentra en una zona de relativamente baja extinción en el tercer cuadrante del plano
galáctico, a una distancia de entre 4 y 6 kpc. En el caso de grupos estelares ubicados a distancias superiores al kiloparsec, la determinación de miembros se vuelve extremadamente compleja, necesitando aplicar
varias técnicas con el fin de obtener resultados confiables. En este trabajo, mostraremos cuan potente es investigar a los miembros de una asociación estelar empleando para ello técnicas astrométricas y astrofı́sicas,
simultáneamente. La búsqueda astrométrica se realiza utilizando los datos del catálogo UCAC4 y empleando el método de Orellana et al. (2010, A&A, 521, A39) para separar los miembros de la asociación de las
estrellas de campo. Luego, se prosigue efectuando un análisis al grupo astrométrico, empleando datos fotométricos y espectroscópicos propios y de bases de datos, obteniendo con ello el listado final de miembros
de Bochum 7. Del estudio de las caracterı́sticas fı́sicas de cada uno de sus miembros, finalmente resulta
posible conocer las componentes del movimiento propio medio, edad, distancia, velocidad radial media,
etc., de la asociación OB Bochum 7.
B
1
2
3
[email protected]
Facultad de Ciencias Astronómicas y Geofı́sicas, Universidad Nacional de La Plata, Argentina
Instituto Argentino de Radioastronomı́a (CCT-La Plata, CONICET), Argentina
Instituto de Astrofı́sica de La Plata (CCT-La Plata, CONICET), Argentina.
62
Short Talks
Stars & Stellar Systems
SSS -6
A photometric study of M67: anchoring measurements for the determination of
astrophysical parameters of bright stars
Dalle Mese, G.B1 ; Lopez-Cruz O.1 ; Schuster, W.2 ; Chavarria, C.2 ; Garcia, G2
We present the photometric analysis of the stars in M67 open cluster. We have performed uvby-Hbeta Stromgren observations using the OAN-SPM 84 cm telescope + CCD and 1.5 m + Danish Spectrophotometer. We
have compared our photometric measurements with CHORIZOS (Maiz-Apellaniz, J. 2004) in order to generate stellar physical parameters and the age of the cluster is modeled with the Dartmouth Stellar Evolution
Database (Dotter et al., 2008). This is the first result of a comprehensive photometric program carried out in
SPM for the generation of a set of secondary standards for the Stromgren system
B
1
2
[email protected]
Instituto Nacional de Astrofisica, Optica y Electronica
Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, sede Ensenada
63
Stars & Stellar Systems
Short Talks
SSS -6
The GALEX Nearby Young-Star Survey
B1
Rodriguez, David R.
; Zuckerman, B.2 ; Kastner, Joel H.3 ; Bessell, M. S.4 ; Faherty, Jacqueline K.1,5,6 ; Murphy, Simon J.7 ;
Vican, Laura2
Over the last few decades, many 10-100 Myr-old stars have been identified in moving groups located closer
than 100 parsecs to Earth. For direct imaging searches of extrasolar planets these stars represent the best
targets and they will be continuously observed during the coming decades as new imaging systems and
larger telescopes are commissioned. Recent work has shown that near-IR surveys, like 2MASS, combined
with ultraviolet data from GALEX can be used to identify additional members in these moving groups. In
particular, this methodology is well suited to searching for low-mass stars, which are generally lacking in
moving group member statistics. Initial searches for young stars relied on optical identification (such as
with Tycho and Hipparcos) and X-ray detection with ROSAT. The release of the all-sky WISE catalog has
opened up a new frontier in the search for nearby, young, low-mass stars. We have carried out an all-sky
cross correlation between the GALEX, WISE, and 2MASS databases and identified many candidate young,
low-mass stars on the basis of their ultraviolet and near-IR colors as well as kinematic information. Early
spectroscopic results confirm the youthful nature of our candidates. This suggests that our technique is
capable of identifying the many low-mass stars that remain to be found among the nearby young moving
groups.
B
1
2
3
4
5
6
7
[email protected]
Universidad de Chile
University of California, Los Angeles
Rochester Institute of Technology
Australian National University
American Museum of Natural History
Carnegie Department of Terrestrial Magnetism
Astronomisches Rechen-Institut, University of Heidelberg
64
Short Talks
Stars & Stellar Systems
SSS -6
The Gaia-ESO Survey: detailed abundances for thousands of FGK-type stars
Smiljanic, RodolfoB1
The Gaia-ESO Survey (GES) is an ambitious public spectroscopic survey that is obtaining medium- and highresolution spectra of more than 105 stars with the FLAMES multi-fiber facility at the VLT. Giraffe mediumresolution spectra will be obtained for ⇠ 105 stars and high-resolution UVES spectra will be obtained for
about 5 000 stars. The targets have been selected to cover all major components of the Galaxy (the halo, the
thick and thin disks, and the bulge) and a significant sample of open clusters (⇠100) covering different ages,
masses, and distances. The ambitious ultimate goal is to provide detailed distribution functions of kinematics and element abundances for stars in all Galactic components, giving a detailed view of the formation and
evolution history of the Galaxy. In this talk, I will introduce the Survey and its goals, with emphasis on the
sample of more than 5 000 FGK-type stars that is being observed in the solar neighbourhood and in open
clusters. I will discuss how the spectra are being analysed and which data products will be made available
to the community through annual public releases. Finally, I will also present some examples of early science
results obtained with Survey data.
B
1
[email protected]
Nicolaus Copernicus Astronomical Center, Torun, Poland
65
Stars & Stellar Systems
Short Talks
SSS -6
The WFCAM Variable Star Catalog and New Variability index
Ferreira Lopes, C. E.B1 ; Dekany, I.2 ; Catelan, C.2 ; Angeloni, R.2 ; De Medeiros, J. R.1
WFCAM is the wide-field near-infrared camera of the 3.8m United Kingdom Infrared Telescope (UKIRT), designed to be capable of carrying out ambitious large-scale survey programs such as the UKIRT Infrared Deep
Sky Surveys that show photometric data in at least 8 bands (Y,Z,J,H,K,H2,nBr,nbj). This data is showing a
”treasures data” to analyse varibility source in infrared. In this way, we present the catalog with 245 identified variable stars shown its characteristics from a data miner’s point of view. We found a total of 49 stars that
were already known from previous studies: in particular, 28 sources are included in the NSVS catalog and,
among them, 3 are also GCVS objects (i.e., AM Tau, EH Lyn, UV Vir – an Algol-type eclipsing binary, a contact binary, and a RRab Lyrae, respectively). In the other side, the tremendous development in astronomical
instrumentation have been giving rise to several synoptic surveys of increasing scale of data thus requiring
that there was an improvement of the tools of data analysis. So, we present a set of new variability indices
that shown be three times more efficient than Stetson index. Moreover, these variability indices represents a
new look at the time series data from view point from signal correlation among the subset of data.
B
carlos [email protected]
DFTE, Universidade Federal do Rio Grande do Norte, Natal, RN, 59072-970 Brazil
2 Departamento de Astronomı́a y Astrofı́sica, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 782-0436 Macul,
Santiago, Chile
1
66
Short Talks
Stars & Stellar Systems
VVV-1
The VVV Survey
D. MinnitiB1 ; VVV Science Team
The Vista Variables in the Via Lactea Survey (VVV) is a public near-IR variability survey scanning the Milky
Way bulge and an adjacent section of the disk. The main goal of the VVV Survey is to map the 3D structure
of the Galactic bulge and decide among different models of bulge formation. The survey will take 193 nights
of observations with the ESO 4-m VISTA telescope between 2010 and 2016, covering a billion point sources
across an area of 540 deg2 . The final product will be a deep near-IR atlas in the YZJHKs passbands (0.9-2.5
µm), and a catalogue of more than a million variable point sources. The Survey has already produced a
number of scientific results and discoveries that will be presented in this talk.
B
1
[email protected]
P. Universidad Catolica de Chile
67
Stars & Stellar Systems
Short Talks
VVV-1
Variable stars in the VVV globular clusters
Alonso-Garcı́a, J.B1,2 ; Dékány, I.1,2 ; Catelan, M.1,2 ; Contreras, R.1,2 ; Minniti, D.1,2,3
The VVV survey is observing the central regions of our Galaxy in the near-infrared, where the extinction is
highly diminished, in several epochs. Numerous inner Galactic globular clusters fall inside the area covered
by the VVV survey. Most of these clusters, especially the faintest ones, have been poorly studied due to the
presence of severe extinction and high stellar densities in the field. We will present the first results of a search
for variable stars we are conducting in these clusters. Our main aim is to obtain a better determination of
the physical parameters of these globular clusters using the information provided by their variables.
B
1
2
3
[email protected]
Instituto de Astrofı́sica, Facultad de Fı́sica, Pontificia Universidad Católica de Chile, Santiago, Chile
The Milky Way Millennium Nucleus, Santiago, Chile
Vatican Observatory, Vatican City State, Italy
68
Short Talks
Stars & Stellar Systems
VVV-1
Searches for variability in the Milky Way bulge with the VVV Survey
R. K. SaitoB1 ; D. Minniti2,3,4 ; F. Gran2 ; D. Iglesias2 ; G. Muro2 ; I. Dekany2,3
The Vista Variables in the Via Lactea (VVV) is an ESO public near-IR variability survey scanning the Milky Way
bulge and southern Galactic disk. VVV is producing a ZYJHKs catalogue of about a billion sources over an
area of 562 square degrees and upon completion will deliver Ks-band light-curves for a few million variable
sources with 80-100 data-point covering many years.
Data taken during 2010-2012 covered the whole VVV bulge area in the five passbands, plus up to 30-40
Ks-band epochs with a large baseline. This data set allow us to search for variability in the Galactic bulge
using different strategies. In this talk we will summarize the first results from this search, from the study of
tiny variations due to planetary transits, until the discovery of hundreds of long period variables, and the
detection of microlensing events and explosive Galactic Nova eruptions.
B
1
2
3
4
[email protected]
Departamento de Fisica, Universidade Federal de Sergipe
Instituto de Astrofisica, Pontificia Universidad Catolica de Chile
The Milky Way Millennium Nucleus
Vatican Observatory
69
Stars & Stellar Systems
Short Talks
VVV-1
The general catalog of VISTA variables in the Via Lactea
Istvan DekanyB1 ; Joyce Pullen; Dante Minniti; Marcio Catelan
The VISTA Variables in the Via Lactea (VVV) ESO Public Survey is providing deep, long-baseline timeseries photometry in the near-infrared for hundreds of millions of objects in the bulge and the southern
disk. The scientific potential of these data is manifold, and its global exploration requires homogeneous
and high-level data products. In my talk, I will expound on the details of a massive computational effort to
produce a general variability database and a catalog of periodic and transient variables in the bulge, using
photometry provided by the VISTA Data Flow System. The goal of this project is to duly provide science-ready
data products in the form of a simple on-line database which may serve as the basis for various specific
studies from stellar pulsation to microlensing, conducted by the VVV community. I will discuss the main
steps of the procedure, the characteristics and possible uses of the database, the current status of the project,
and will conclude by highlighting selected results.
B
1
[email protected]
Instituto de Astrofisica, Pontificia Universidad Catolica de Chile
70
Short Talks
Stars & Stellar Systems
SSS -7
A new insight to the O Vz stars within the framework of the GOSS Survey
Arias, J. I.B1 ; Maı́z Apellániz, J.2 ; Barbá, R. H.1 ; Walborn, N. R.3 ; Sota, A.2 ; Morrell, N. I.4 ; Alfaro, E.2 ; Gamen, R. C.5
Based on high-S/N observations from both hemispheres, the Galactic O-Star Spectroscopic Survey (GOSSS)
is the largest collection of O-star optical spectra ever assembled. Because of the quality, quantity, and homogeneity of the data, this survey has produced several systemic developments and revisions, some of them
unexpected, for the massive hot stars. Beside having improved the definition of the spectral-classification
system, GOSSS is revealing numerous objects and categories of special interest, also allowing their statistical
study. The present work constitutes a further example. It is focused on the Galactic members of the Vz luminosity class, in which He II 4686 absorption is stronger than any other He II or He I lines. This characteristic
has been hypothesized to be a signature of the extreme youth of the objects, as the stellar winds responsible
for the emission filling of the former line would be less developed than even at class V. We investigate systematically the Galactic O Vz stars, finding a number of curious effects regarding their distribution as a function
of spectral type. The definition of what it means to be an O Vz star, along with the astrophysical significance
of this category, is also rediscussed.
B
1
2
3
4
5
[email protected]
Universidad de La Serena, Chile
Instituto de Astrofı́sica de Andalucı́a, España
Space Telescope Science Institute, USA
Las Campanas Observatory, Chile
Universidad Nacional de La Plata, Argentina
71
Stars & Stellar Systems
Short Talks
SSS -7
OWN Survey: results after seven years of high-resolution spectroscopic monitoring of
Southern O and WN stars
Barba, R. H.B1 ; Gamen, R.2 ; Arias, J.1 ; Morrell, N. I.3 ; Walborn, N.4 ; Maiz Apellaniz, J.5 ; Alfaro, E.5 ; Sota, A.5
The high-resolution spectroscopic monitoring survey of O and WN stars (OWN Survey) has completed seven
years of continuous campaigning, using observational facilities of Chile and Argentina. The sample was
selected corresponds to those stars for which there is no indication of multiplicity in the Galactic O-star
Catalog (Maiz Apellaniz et al. 2004) and the VII Catalogue of Galactic WR stars (van der Hucht 2000). We
have collected over 4000 spectra of about 200 O and WN stars which has allowed us to discover 126 stars
showing radial variations greater than 10 km/s. From these stars: 101 new systems, being 53 single-lined
spectroscopic binaries, 40 double-lined spectroscopic binaries, and 8 multiple-lined binaries. The new orbital periods spanning from 1.5 to 2200 days. In this work, we present the main result of ”OWN Survey”: the
determination of orbits for over forty O-type spectroscopic binary systems. This result is unprecedented in
the context of massive binary stars, since we almost doubling the number of systems with known orbits. We
analyse the distribution of orbital elements, mass function, mass ratio, spectral types, etc.
B
1
2
3
4
5
[email protected]
Universidad de La Serena
Instituto de Astrofisica La Plata - CONICET
Las Campanas Observatory
Space Telescope Science Institute
Instituto de Astrofisica de Andalucia - CSIC
72
Short Talks
Stars & Stellar Systems
SSS -7
Overview of Stellar Interferometry and its contribution to the study of massive stars
Kanaan, S.B1 ; Meilland, A.2 ; Millour, F.2 ; Cure, M.1 ; Chesneau, O.2 ; Borges, M.3 ; Cidale, L.4 ; Arcos, C.1
This talk is an overview of stellar interferometry applied to Be and B[e] phenomena.
Hot Active stars are an important source of UV photons that are ionizing the circumstellar and interstellar
environment up to a few hundred of parsecs. Thus, they are playing an important role in the heating of the
gas in the arms of galaxies as well as the formation of radiative shocks in the interstellar medium.
These stars are very bright and over luminous compared to B “normal” stars due to the presence of their
circumstellar envelope. Thus, in young clusters, with many Be stars, the luminosity function may seem to
contain too massive stars, leading to an artificially top-heavy Initial Mass Function (IMF).
The lack of angular resolution in observations limited the study of these objects and their modelling was
based only on fitting the SED or line profiles. To discriminate between the various physical processes describing the mass loss and the distribution of matter in the circumstellar medium, the geometry and the
kinematics of these envelopes have to be fully constrained. This cannot be done by a single telescope and
long-baseline interferometry is the only available technique to reach the spatial resolution necessary to resolve most of the envelopes. The VLTI instruments AMBER and MIDI and the upcoming instruments such
as MATISSE and GRAVITY are perfectly adapted to the study of these gaseous and dusty environments as
their flux is generally dominated by circumstellar emission beyond 1 µm. Using interferometry with high
resolution spectra allow us to use the differential visibility and differential phase. In fact disks in rotation or
in expansion have the same spectroscopic profile which make it impossible to descriminate between these
two scenarios. On the other hand these scenarios have there own signature in the differential visibility and
phase. Performing many interferometric observations, with different baselines lengths and position angle,
will allow us to reconstruct images with softwares such as MIRA. The advantage of the image reconstruction
lies in the fact that it is independent from any model. Moreover using image reconstruction could reveal the
flattening of the envelope, asymmetries in the disk such as spiral arm, clumpiness or binarity.
B
1
2
3
4
[email protected]
Universidad de Valparaiso, departamento de fisica y astronomı́a
Laboratoire Lagrange, Universite de Nice Sophia-Antipolis, CNRS, Observatoire de la Cote d’Azur
Observatorio Nacional, Rio de Janeiro
Instituto de Astrofısica de La Plata, CCT-La Plata, CONICET & Facultad de Ciencias Astronomicas y Geofisicas, UNLP
73
Stars & Stellar Systems
Short Talks
SSS -7
Integral Field Unit spectroscopy of supernova host galaxies
B1,2
Lluı́s Galbany
; Vallery Stanishev1 ; Ana Mourão1 ; Myriam Rodrigues3 ; Hector Flores4 ; CALIFA Collaboration
We used optical IFU spectroscopy of nearby SN host galaxies (0.005 < z < 0.03), obtained by the CALIFA
Survey and from previous observations, in order to look for correlations between the SN type and the environmental parameters at the location of the explosion. After subtracting the stellar continuum emission, we
produced spatially resolved maps of several ionized gas emission lines and stellar population parameters.
We found differences in the galactocentric distances distributions in a sequence from Ibc to Ia, being type II
in the middle of those. After selecting the nearest HII region we found core collapse SNe tending to explode
closer than SNe Ia. This can be explained by differences in ages and masses among the parent stellar populations of the progenitors of different SN types. In addition, we also found slightly differences in the local
elemental abundances of type Ibc and type Ia compared to type II SNe. Once distances are normalized to the
effective radius, the metallicity gradient seems to be universal, and differences between the value at the SN
position and that obtained from the gradient can be established. We finally compared the values measured
at the galaxy core, SN position, and co-adding all the galaxy emission, finding significant differences among
them, especially for SNe Ia, which tend to explode in metal-rich environments.
B
1
2
3
4
[email protected]
CENTRA - Centro Multidisciplinar de Astrofı́sica, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
Departamento de Astronomı́a, Universidad de Chile, Casilla 36-D, Santiago, Chile
European Southern Observatory, Alonso de Cordova 3107 Casilla 19001 - Vitacura -Santiago, Chile
GEPI, Observatoire de Paris, UMR 8111, CNRS, Université Paris Diderot, 5 place Jules Janssen, 92190 Meudon, France
74
Short Talks
Stars & Stellar Systems
SSS -7
Subluminous type Ia supernovae
Gonzalez-Gaitan, S.B1
We present a thorough photometric and spectroscopic study of a large sample of subluminous type Ia supernovae (SNe Ia) comparing them to the normal type Ia population. Subluminous SNe Ia are characterized by
strong Ti II and enhanced Si II lines, they are fainter, redder and have fast evolving light-curves. Due to their
outlying differences they have been left out of cosmological studies but they are key to understand SNIa
progenitors. We show that subluminous SNe Ia can be clearly identified via spectroscopic but also purely
photometric techniques of current and upcoming surveys, and we present some of their key features that
enable us to characterize their progenitor systems.
B
1
[email protected]
Departamento de Astronomia, Universidad de Chile
75
Stars & Stellar Systems
Short Talks
SSS -8
Supernova remnants colliding with molecular clouds: From high- to low-energy
interactions
Montmerle, T.B1
It is now well established that a class of gamma-ray sources in the galactic plane, especially in the TeV range
as seen by HESS and other Cerenkov telescopes, and in the GeV range by the Fermi and AGILE satellites,
is associated with intermediate-age supernova remnants interacting with molecular clouds in massive starforming regions. After a brief general introduction linking high-energy gamma-rays and cosmic rays, I will
focus on a few such gamma-ray sources (W28, W44, and W51) and the challenging conclusions that can be
drawn from them. I will then describe our recent work on related submm measurements and implications
of enhanced ionizing effects in molecular clouds due to locally accelerated low-energy cosmic rays.
B
1
[email protected]
Institut d’Astrophysique de Paris, France
76
Short Talks
Stars & Stellar Systems
SSS -8
A new class of type Ia Supernovae
Pignata G.B1 ; Taubemberger S.2 ; Kromer, M.2 ; Pakmor R.3
I will present evidences for a new class of type Ia SNe which have low luminosity, red colors and absence of a
secondary maximum typical of sub-luminous type Ia SNe but display a slow rice to maximum and also a slow
post-maximum decline which place them completely out of standard light curve width-luminosity relation
of SNe Ia. This study starts from the observational campaign on SN2010lp carried out by the Millennium
Center for Supernova Science (MCSS), but subsequently include other peculiar SNe Ia from the literature
which display similar photometric and spectroscopic properties. SN2010lp is the first ever observed type
Ia SN showing oxygen emission line on its nebular spectrum. The [0I] features has a complex profile with
a broad base and two narrow emission peaks superimposed which suggests that oxygen is distributed in
a non-spherical region close to centre of the ejecta. The latter pointed to a violent merger of two white
dwarf (Pakmor et al. 2012,2013) as the most promising scenario for this SN. Base on this explosion model
we generate, through a complete radiative transfer simulations, light curve and spectra at the photospheric
phase which match quite well the observed light curve and spectra of SN2010lp reinforcing the hypothesis
this SN and probably the other peculiar SNe Ia we consider in this study come for this progenitor channel.
B
1
2
3
[email protected]
Universidad Andrés Bello
Max-Planck-Institut für Astrophysik
Heidelberger Institut für Theoretische Studien
77
Stars & Stellar Systems
Short Talks
SSS -8
Recurrent solar coronal jets induced by magnetic emergence
Y. Guo1,2 ; P. Démoulin3 ; B. Schmieder3 ; M. D. Ding1,2 ; S. Vargas Domı́nguezB4 ; Y. Liu5
Jets of plasma are frequently observed in the solar corona. A self-similar recurrent behavior is observed in a
fraction of them. These jets are thought to be a consequence of magnetic reconnection, however, the physics
involved is not fully understood. Therefore, we study some jet observations with unprecedented temporal
and spatial resolutions with data from the Solar Dynamics Observatory (SDO). We derive the magnetic flux
evolution, the photospheric velocity field, and the vertical electric current evolution. The magnetic configuration before the jets is derived by the nonlinear force-free field (NLFFF) extrapolation. Three EUV jets
recurred in about one hour on 2010 September 17 in the following magnetic polarity of active region 11106.
We derive that the jets are above a small magnetic bipole which is continuously driven by photospheric diverging flows. The interaction drove the build up of electric currents that we indeed observed as elongated
patterns at the photospheric level. For the first time, the high temporal cadence of HMI allows to follow
the evolution of such small currents. In the jet region, we found that the integrated absolute current peaks
repetitively in phase with the 171 Å flux evolution. The photospheric current pattern of the jets is found
associated to the quasi-separatrix layers deduced from the magnetic extrapolation. From previous theoretical results, the observed diverging flows are expected to build continuously such currents. We conclude that
magnetic reconnection occurs periodically, in the current layer created between the emerging bipole and the
large scale active region field. It induced the observed recurrent coronal jets and the decrease of the vertical
electric current magnitude.
B
1
2
3
4
5
[email protected]
School of Astronomy and Space Science, Nanjing University, Nanjing 210093, China
Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education, Nanjing 210093, China
LESIA, Observatoire de Paris, CNRS, UPMC, Université Paris Diderot, 5 place Jules Janssen, 92190 Meudon, France
Departamento de Fı́sica, Universidad de Los Andes, A.A. 4976, Bogotá, Colombia
W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305, USA
78
Short Talks
Stars & Stellar Systems
SSS -8
Mass extinctions, galactic orbits in the solar neighborhood and the Sun: a connection?
Gustavo F. Porto de MelloB1 ; Wilton S. Dias2 ; Jacques Lépine3 ; Diego Lorenzo-Oliveira1 ; Rodrigo Kazu Siqueira4
The orbits of the stars in the disk of the Galaxy, and their passages through the Galactic spiral arms, are a
rarely mentioned factor of biosphere stability which might be important for long-term planetary climate
evolution, with a possible bearing on mass extinctions. The Sun lies very near the co-rotation radius, where
stars revolve around the Galaxy in the same period as the density wave perturbations of the spiral arms.
Conventional wisdom generally considers that this status makes for few passages through the spiral arms.
Controversy still surrounds whether time spent inside or around spiral arms is dangerous to biospheres and
conducive to mass extinctions. Possible threats include giant molecular clouds disturbing the Oort comet
cloud and provoking heavy bombardment; a higher exposure to cosmic rays near star forming regions triggering increased cloudiness in Earth’s atmosphere and ice ages; and the destruction of Earth’s ozone layer
posed by supernova explosions. We present detailed calculations of the history of spiral arm passages for
all 212 solar-type stars nearer than 20 parsecs, including the total time spent inside the spiral arms in the
last 500 Myr, when the spiral arm position can be traced with good accuracy. We found that there is a large
diversity of stellar orbits in the solar neighborhood, and the time fraction spent inside spiral arms can vary
from a few percent to nearly half the time. The Sun, despite its proximity to the galactic co-rotation radius, has exceptionally low eccentricity and a low vertical velocity component, and therefore spends 30% of
its lifetime crossing the spiral arms, more than most nearby stars. We discuss the possible implications of
this fact to the long-term habitability of the Earth, and possible correlations of the Sun’s passage through
the spiral arms with the five great mass extinctions of the Earth’s biosphere from the Late Ordovician to the
Cretaceous-Tertiary.
B
1
2
3
4
[email protected]
Observatório do Valongo, Universidade Federal do Rio de Janeiro
Instituto de Ciências Exatas, Universidade Federal de Itajubá
Instituto Astronômico, Geofı́sico e de Ciências Atmosféricas, Universidade de São Paulo
Instituto Carlos Chagas Filho de Biofı́sica, Universidade Federal do Rio de Janeiro
79
Stars & Stellar Systems
Short Talks
VVV-2
Reddening-Free Indices in the VISTA Filter System
Catelan, M.B1 ; Leyton, P.
Accurate interstellar extinction values represent one of the most important items in every astronomer’s wish
list. Unfortunately, extinction is notoriously difficult to measure, and thus represents a serious challenge
in the era of high-precision astronomy. In this sense, reddening-free indices can be of considerable astrophysical importance, as they allow analysis of several problems without the need for accurate foreground
reddening values. In this paper, we describe our efforts towards generalizing the reddening-free indices in
the VISTA filter system that were first defined in Catelan et al. (2011), by evaluating their dependence on
spectral type and luminosity class.
B
1
[email protected]
Pontificia Universidad Catolica de Chile, Instituto de Astrofisica
80
Short Talks
Stars & Stellar Systems
VVV-2
Near-Infrared Photometric Parameters of Galactic Globular Clusters From the VVV
Survey
Cohen, R. E.B1 ; Mauro, F.1 ; Moni Bidin, C.1 ; Geisler, D.1 ; Villanova, S.1
We present results from near-infrared photometry of Galactic globular clusters located towards the Galactic
bulge from the Vista Variables in the Via Lactea (VVV) survey. In light of updated spectroscopic abundance
information, correlations between photometric parameters and cluster metallicities are examined and compared to predictions from evolutionary models, with the large survey area permitting statistical field star
decontamination. These data are supplemented with additional high spatial resolution optical and infrared
photometry, facilitating not only photometric analyses over a broad color baseline, but also new constraints
on the reddening and reddening law in the direction of these clusters as well as their structural parameters.
B
1
[email protected]
Universidad de Concepcion
81
Stars & Stellar Systems
Short Talks
VVV-2
Study of Young Stellar Clusters in the Nebular Complex NGC6357 with VVV
Lima, E. F.B1 ; Bica E.1 ; Bonatto C.1 ; Saito R. K.2
NGC 6357 is a very active star-forming complex seen in the optical as an extensive H II region located in the
Sagittarius spiral arm. We are studying several star clusters in NGC 6357 doing a matching of the 2MASS and
VVV data. The 2MASS data were used for the brightest objects (Ks < 11 mag), while VVV was used for the
fainter objects. To disentangle field and cluster stars we employed the statistical decontamination algorithm
described in Bonatto & Bica 2010. Our analysis has provided a preliminary view of the Colour Magnitude
Diagrams (CMD) and density structure of these objects, and also basic information about the behavior of
the interstellar medium in the complex.
B
1
2
[email protected]
Universidade Federal do Rio Grande do Sul - Brazil
Universidade Federal de Sergipe - Brazil
82
Short Talks
Stars & Stellar Systems
VVV-2
Proper motions and brown dwarfs in the VVV survey
B1
Beamı́n, J. C.
; Minniti, D.1,2,3 ; Gromadzki, M.4 ; Kurtev, R.4 ; Ivanov, V. D.5 ; Lucas, P.6 ; Saito, R. K.7 ; Borissova, J.4
The Vista Variables in the Vı́a Láctea (VVV) survey is a deep multi wavelength, multi-epoch, Near infrared
survey of the Galactic inner disk and bulge covering 560deg2 in the sky. We started a search for High Proper
Motions -HPM ( PM>0.1 ”/yr) objects in the VVV database, using the Ks band observations from 2010 until
2012. We have found and recovered hundreds of HPM objects. Our studies are complementary to other
HPM surveys, especially considering we target very crowded and heavily extincted regions, also our survey is
particularly sensitive to detect low mass stars, ultra cool dwarfs because of the use of deep near-IR data. The
higher spatial resolution and multi-epoch data, help us to reveal HPM objects that were hidden by confusion
with background sources in previous observations. As an example of the success of this approach we present
the first brown dwarf discovered in the VVV survey, an unusually blue L dwarf at 17.5 pc of the Sun (Beamı́n
et al. 2013 submitted). VVV data also allows us to calculate parallaxes of nearby objects up to ⇠20-30 pc.
B
[email protected]
Instituto de Astrofı́sica, Facultad de Fı́sica, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile
2 The Milky Way Millennium Nucleus, Av. Vicuña Mackenna 4860, 782-0436 Macul, Santiago, Chile
3 Vatican Observatory, Vatican City State V-00120, Italy
4 Departamento de Fı́sica y Astronomı́a, Facultad de Ciencias, Universidad de Valparaı́so, Ave. Gran Bretaña 1111, Playa Ancha,Valparaı́so
Chile
5 European Southern Observatory, Ave. Alonso de Cordoba 3107, Casilla 19001, Santiago, Chile
6 Centre for Astrophysics Research, Science and Technology Research Inst., University of Hertfordshire, Hatfield AL10 9AB, UK
7 Universidade Federal de Sergipe, Departamento de Fı́sica, Av. Marechal Rondon s/n, 49100-000, São Cristóvão, SE, Brazil
1
83
Stars & Stellar Systems
Short Talks
VVV-2
Weather on Other Worlds: Brown Dwarf variability and VVV
B1
Kurtev, R.
; Metchev, S.2 ; Heinze, A.2 ; Gromadzki, M.1 ; Ivanov, V. D.3 ; Minniti, D.4 ; Beamin, J. C.4 ; Borissova, J.1
L/T transition brown dwarfs present large-amplitude variability on rotational timescales. Photometric monitoring from warm Spitzer reveals that the L3 dwarf DENIS-P J1058.7-1548 varies sinusoidally in brightness
with a period of ⇠4.25 hr and an amplitude of ⇠0.4% (peak-to-valley) in the 3.6µm band, confirming the
reality of a 4.3±0.3hr periodicity detected in J-band photometry from the SOAR telescope. The J-band vari-
ations are a factor of 2.2±0.3 larger in amplitude than those at 3.6µm, while 4.5µm Spitzer observations yield
a 4.5/3.6µm amplitude ratio of only 0.23±0.15, consistent with zero 4.5µm variability. This wide range in amplitudes indicates rotationally modulated variability due to magnetic phenomena and/or inhomogeneous
cloud cover. However, inhomogeneous cloud cover alone can explain all our observations, and our data align
with theory in requiring that the regions with the thickest clouds also have the lowest effective temperature.
DENIS-P J1058.7-1548 is only the first of nearly two dozen low-amplitude variables discovered and analyzed
by the Weather on Other Worlds project. Here we present also variability results for another two of our targets based on SPARTAN/SOAR and SOFI/NTT NIR observations as well as long term variability from the VVV
survey for some additional VVV targets.
B
1
2
3
4
[email protected]
Departamento de Fisica y Astronomia, Universidad de Valparaiso
Department of Physics and Astronomy, Stony Brook Univesity
European Southern Observatory
Departamento de Astronomia, Pontificia Universidad catolica de Chile
84
Star Formation
SF -1
Observational diagnostics of young stellar objects in NGC 2264
Silvia AlencarB1 ; Jerome Bouvier2 ; John Stauffer3 ; CSI2264 Team
We present the results of a multiwavelength observational campaign of the young (⇠ 3 Myr) open cluster
NGC 2264. The cluster was observed simultaneously for about a month with the CoRoT, MOST and Spitzer
satellites in December 2011 and January 2012. We also obtained 3.5 days of Chandra observations at the
same epoch, together with 20 epochs of FLAMES (VLT-ESO) multi-object spectrocopy and U band photometry with Megacam at CFHT. We have identified several classes of objects with optical light curves that are
dominated by either by cold spots, extinction by circumstellar material or variable accretion events. We
show that we can characterize, with both photometric and spectroscopic data, the different physical processes taking place at the stellar surface and its circumstellar environment of young low mass systems.
B
1
2
3
[email protected]
DF-ICEx, UFMG, Brazil
IPAG, Grenoble, France
Caltech, USA
85
Star Formation
Short Talks
SF -1
The SONYC survey: Towards a complete census of brown dwarfs in star forming regions
Kora MuzicB1 ; Aleks Scholz2 ; Ray Jayawardhana3 ; Vincent C. Geers4 ; P. Dawson4 ; T. P. Ray4 ; M. Tamura5
Deep surveys of star forming regions are the backbone of observational studies on the origin of stars and
planets: On one side, they provide large and homogeneous object samples required to study disks, accretion,
and multiplicity. On the other side, such surveys determine the shape and the low-mass limit of the Initial
Mass Function (IMF), which are fundamental constraints on star formation theory.
SONYC, short for “Substellar Objects in Nearby Young Clusters”, is an ongoing project to provide a census of the substellar population in nearby star forming regions. We have conducted deep optical and nearinfrared photometry, combined with proper motions, and followed by extensive spectroscopic follow-up
campaigns with Subaru and VLT, in which we have obtained more than 700 spectra of candidate objects in
NGC1333, ⇢ Ophiuchi, Chamaeleon-I, Upper Sco, and Lupus-3. We have identified and characterized more
than 60 new substellar objects, among them a handful of objects with masses close to, or below the Deuterium burning limit. Thanks to the SONYC survey and the efforts of other groups, the substellar IMF is now
well characterized down to ⇠ 5
10MJ , and we find that the ratio of the number of stars with respect to
brown dwarfs lies between 2 ad 6. Another important piece of information for the star formation theories
is that, down to ⇠ 5MJ , the free-floating objects with planetary masses are 20-50 times less numerous than
stars, so that their total contribution to the mass budget of the clusters can be neglected.
In this contribution we will present the status of the SONYC survey, discuss its main results, and focus on
the latest findings in NGC1333, Lupus-3 and Upper-Sco.
B
1
2
3
4
5
[email protected]
European Southern Observatory (ESO), Chile
School of Physics & Astronomy, St. Andrews University, United Kingdom
Department of Astronomy & Astrophysics, University of Toronto, Canada
School of Cosmic Physics, Dublin Institute for Advanced Studies, Ireland
National Astronomical Observatory of Japan, Tokyo, Japan
86
Short Talks
Star Formation
SF -1
Millimeter and Far-IR observations of the IRDC G341.24-0.27
Vasquez, J.B1,2 ; Cappa, C.1,2 ; Romero, G.2 ; Rubio, M.3
Infrared Dark Clouds (IRDCs) are the cold T < 25 K) and dense (> 105 cm
and a mass of 10⇥
2 5
3
) regions, with a scale of 1 - 10 pc
M . Cores within the IRDCs may be in different phases, from a quiescent to an active
one. Quiescent cores represent the earliest protostellar (starless) core phase without infrared signatures of
star formation, commonly observed at far IR wavelengths, while active cores have extended and enhanced
4.5µm emission.
In this work, we analyze CO(2-1), 13CO(2-1), and CO(2-1) lines, and mid- and far-infrared data towards
the EGOS (Extended Green Objects) G341.23-0.27 and G341.22-0.26(a), projected onto the IRDC G341.240.27.
B
1
2
3
[email protected]
Instituto Argentino de Radioastronomı́a, CONICET, Argentina
Facultad de Ciencias Astronómicas y Geofı́sicas de La Plata, Argentina
Departamento de Astronoı́mia, Universidad de Chile
87
Star Formation
Short Talks
SF -1
A X-ray view of young star population in CMa R1
Santos-Silva, T.B1 ; Gregorio-Hetem, J.1 ; Montmerle, T.2
In previous works we studied the star formation scenario in the molecular cloud Canis Major R1 (CMa R1),
derived from the existence of young stellar population groups near the Be stars Z CMa and GU CMa. Using
data from the ROSAT X-ray satellite, having a field-of-view of ⇠ 1o in diameter, Gregorio-Hetem et al. (2009)
discovered in this region young stellar objects mainly grouped in two clusters of different ages, with others
located in between. In order to investigate the nature of these objects and to test a possible scenario of
sequential star formation in this region, four fields (each 30 arcmin diameter, with some overlap) have been
observed with the XMM-Newton satellite, with a sensitivity about 10 times better than ROSAT.
The XMM-Newton data are currently under analysis. Preliminary results indicate the presence of about
324 sources, most of them apparently having one or more near-infrared counterparts showing typical colors
of young stars. The youth of the X-ray sources was also confirmed by X-ray hardness ratio diagrams (XHRD),
in different energy bands, giving an estimate of their Lx/Lbol ratios.
In the present work we show the results of the study based on the spectra of about 150 sources found in
four XMM fields. We checked that the X-ray spectra (0.3 to 10 keV) of young objects is different from that
observed in field stars and extragalactic objects. Some of the candidates also have light curve showing flares
that are typical of T Tauri stars, which confirms the young nature of these X-ray sources.
B
1
2
[email protected]
Instituto de Astronomia Geofı́sica e Ciências Atmosféricas, Departamento de Astronomia
Institut d’Astrophysique de Paris
88
Short Talks
Star Formation
ISM -1
The role of reconnection diffusion in the gravitational collapse of turbulent cloud cores
Leão, M. R. M.1 ; de Gouveia Dal Pino, E. M.2 ; Santos-Lima, R.B2 ; Lazarian, A.3
For a molecular cloud clump to form stars some transport of magnetic flux is required from the denser, inner
regions to the outer regions of the cloud, otherwise this can prevent the collapse. Fast magnetic reconnection which takes place in the presence of turbulence can induce a process of reconnection diffusion (RD).
Extending earlier numerical studies of reconnection diffusion in cylindrical clouds, we consider more realistic clouds with spherical gravitational potentials and also account for the effects of the gas self-gravity. We
demonstrate that within our setup RD is efficient. We have also identified the conditions under which RD becomes strong enough to make an initially subcritical cloud clump supercritical and induce its collapse. Our
results indicate that the formation of a supercritical core is regulated by a complex interplay between gravity,
self-gravity, the magnetic field strength and nearly transonic and trans-Alfvénic turbulence, confirming that
RD is able to remove magnetic flux from collapsing clumps, but only a few of them become nearly critical
or supercritical, sub-Alfvénic cores, which is consistent with the observations. Besides, we have found that
the supercritical cores built up in our simulations develop a predominantly helical magnetic field geometry
which is also consistent with observations. Finally, we have evaluated the effective values of the turbulent
reconnection diffusion coefficient and found that they are much larger than the numerical diffusion, especially for initially trans-Alfvénic clouds, ensuring that the detected magnetic flux removal is due to to the
action of the RD rather than to numerical diffusivity.
B
1
2
3
[email protected]
Instituto de Matemática, Estatı́stica e Computação Cientı́fica, UNICAMP
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, USP
University of Wisconsin
89
Star Formation
Short Talks
SF -2
The SACY view of the Sco-Cen complex
B1
Claudio H. F. Melo
; Carlos A. O. Torres2 ; Germano R. Quast2 ; Ramiro de la Reza3 ; Juarez B. de Carvalho2
SACY is a program to search for associations containing young stars in the solar neighborhood. For that we
observed spectroscopically and photometrically TYCHO stars that were detected in the ROSAT survey. We
have detected some previously unknown young nearby associations as we published somewhere. Nevertheless most of the young detected stars belong to the Sco-Cen complex, and this enables a new view of this
complex. To better accomplish this we add to our catalog some stars attributed to one of the associations
of the complex, mainly for the ones that have few members in the SACY sample. We have a new view of
the kinematical, spatial, age and Li distribution definitions of LCC, US, UCL, Lupus, rho Oph extension, CrA
extension associations and we can also compare them with other associations that are considered in some
way connected with the complex (as TWA, epsilon Cha, beta Pic and the Cha I/II associations). We show a
new view of the young solar environment from 5 to 15 Myr.
B
1
2
3
[email protected]
ESO
Laboratório Nacional de Astrofı́sica (LNA/MCTI)
Observatório Nacional (ON/MCTI)
90
Short Talks
Star Formation
SF -2
The Role of Local Environment in Stellar Cluster Formation
Carlos G. Román-ZúñigaB1
We will present the results of a comparative analysis of the properties of galactic embedded clusters in various active star forming complexes of the galaxy: B59, W3/W3(OH), W75N/S, Rosette and Sh 2-252. By combining deep, near-IR observations with archive point source catalogs from Spitzer and Chandra Space Telescopes, we compare the young stellar clusters forming in these regions, in terms of their development in the
context of influence from massive star formation, the structure of the molecular cloud in which they form
-analyzed from dust-extinction maps and, when available, dust-emission maps from Herschel Space Telescope. It appears that local triggering by massive clusters could be less important than cloud structure in
determining the formation of secondary and tertiary generations. Clusters form in dense molecular clumps
and evolve rapidly, with class II and class III sources spreading away from prenatal gas in a times comparable to disk-dissipation timescales, while class 0/I sources continue to trace the aggregation of material as the
cloud and form with decreasing efficiency as the available gas is exhausted.
B
1
[email protected]
Instituto de Astronomı́a, Universidad Nacional Autónoma de México
91
Star Formation
Short Talks
SF -2
Deuteration and fragmentation in massive star-forming regions
Rodón, J. A.B1 ; Beuther, H.2 ; Zhang, Q.3 ; Schilke, P.4
In the last decade, we have started to spatially resolve the small gas and dust condensations in high-mass
star-forming regions that will eventually become a massive star or system, finally being able to describe
how those regions fragment. Recent works, for example Palau et al. 2013, show that there is no correlation
between the fragmentation of a region and its physical properties. But what about its chemistry? According
to Fontani et al. 2011, an interesting chemical property to investigate is the deuteration fraction, since it
can be used as a chemical clock. In this contribution we show the fragmentation properties and deuteration
factors obtained for a group of massive star-forming regions with SMA, PdBI, and IRAM-30m observations,
and discuss what the relationship between them tells us.
B
1
2
3
4
[email protected]
European Southern Observatory
Max-Planck Institut für Astronomie
Harvard-Smithsonian Center for Astrophysics
Universität zu Köln
92
Short Talks
Star Formation
SF -2
Formation Models of Cometary Ices in Protoplanetary Disks
Chaparro, G.B1 ; Kamp, I.1
I set out to constrain the chemical conditions in the early Solar System by analyzing chemical evolution
models of protoplanetary disks and comparing them to our current knowledge of Solar System bodies, such
as comets. For this I require a 2D radiative disk model in vertical hydrostatic equilibrium to set the conditions in which the chemistry evolves. Given that the planet (and comet) forming region of disks coincides
with the cosmic-ray dominated midplane of disks, I focus on understanding the role of cosmic ray-induced
photoprocesses, treating them in a way that is consistent with the local dust and gas opacity.
I find that gas opacity in gas-rich regions of the disk midplane is a major contributor to the total opacity.
Gas species formed in this region that drift vertically to optically thin zones may be used to probe the midplane chemical activity. I find that cometary ice species are formed in timescales shorter than the lifetime
of the disk, thus showing that steady-state chemical models underpredict those abundances. I propose that
regions located at r > 10 AU are ideal for the formation of ice mantles that match observed cometary abundances and ice-to-dust mass ratios. I discuss the possibility of trapping ice species formed in early stages
of the disk evolution, thus forming a stratified ice mantle. The growth of an ice mantle contributes to increase significantly the size of dust grains. Such a modification in the dust size distribution will impact the
midplane temperature and the efficiency of dust coagulation.
B
1
[email protected]
Kapteyn Astronomical Institute
93
94
ISM
ISM -1
A new catatalogue of H I supershell candidates in the outer part of the Milky Way
Suad, L. A.B1 ; Caiafa, C. F.1,2 ; Arnal, E. M.1,3 ; Cichowolski, S.4
The interstellar medium, when viewed in the neutral hydrogen (H I) line emission, reveals a complex structure that is evidenced by the presence of inhomogeneities like shells, supershells, arcs, cavities and loops.
In particular H I supershells are minima in the galactic H I emission distribution surrounded completely, or
partially, by ”walls” of enhanced H I emission. Supershells are believed to be created, most likely, by the
action of the powerful stellar winds of massive stars and their subsequent explosion as supernova. Nevertheless, other mechanisms like gamma-ray bursts or high velocity cloud infall have been proposed for those
shells whose kinetic energy is about 1053
54
erg.
In this work we present a new catalogue of H I supershell candidates in the outer part of the Galaxy. Several catalogues of shells and/or supershells have been made using either a visual inspection (Heiles 1979,
1984; McClure-Griffiths et. al 2002) or automatic algorithms (Ehlerová & Palous 2005, 2013; Daigle et al.
2007). In this new catalogue we have used a combination of both visual and automatic identification procedures. One of the main features of our algorithm has to do with the fact that it is able to recognize structures
even when they are not completely surrounded by walls of H I emission. In this respect it is quite different from the automatic detection algorithms used up to now by other researchers. We used the LeidenArgentine-Bonn survey (Kalberla et al. 2005). The catalogue covers most of the second and third galactic
quadrants, except for a region 30 wide centered at 180 (90 < l < 165 and 195 < l < 270 ; 50 < b < 50 ).
We have considered as supershell candidates those structures satisfying the following criteria: I) a linear diameter larger than 200 pc, II) an angular diameter larger than 2 , and III) a velocity extent of at least 6.5k s
1
.
A total of 575 supershells have been catalogued. Only 55% of them are completely surrounded by ”walls” of
enhanced H I emission.
In this work we also analyze the main statistical parameters of the supershell candidates. From the OB
associations and open clusters catalogues we have looked for correlations between these objects and the
supershells. Finally, we have compared our catalogue with the ones made by other authors.
B
1
2
3
4
[email protected]
Instituto Argentino de Radioastronomı́a (IAR), CC 5, 1894, Villa Elisa, Argentina
Facultad de Ingenierı́a, Universidad de Buenos Aires, C.A.B.A., Argentina
Facultad de Ciencias Astronómicas y Geofı́sicas, Universidad Nacional de La Plata, La Plata, Argentina
Instituto de Astronomı́a y Fı́sica del Espacio (IAFE), Cuidad Universitaria, C.A.B.A, Argentina
95
ISM
Short Talks
ISM -1
Photostability of Organic Molecules in Circumstellar Environment
Monfredini, T.B1 ; Wolff, W.1 ; Mendoza, E. F.1 ; Lago, A. F.2 ; Rocco, M. L. M.1 ; Boechat-Roberty, H. M.1
From observational data of interstellar medium we have two clear spectroscopy features in the VIS and UV
wavelength ranges: the unidentified diffuse interstellar bands (DIBs) and the bump at 217.5 nm. Neutral
and ionic Polycyclic Aromatic Hydrocarbons (PAHs), which consist of fused benzene rings, such as naphthalene, anthracene and pyrene, have been found in several astrophysical environments, ranging from planetary nebulae to active galactic nuclei. Toluene (C6 H5 CH3 ), or methyl-benzene molecule, is a basic unit for
the methylated PAHs. Their precursor molecules such as benzene (C6 H6 ), diacetylene (C4 H2 ), triacetylene
(C6 H2 ), methylacetylene (CH3 C2 H) and methyl-diacetylene (CH3 C4 H) were detected in protoplanetary nebulae CRL 618 (Cernicharo et al. 2001a) and in SMP LMC 11 in the Large Magellanic Cloud (Bernard-Salas et
al. 2008). Interaction of UV and X-ray photons from the hot central star ionizes and dissociates molecules
present in its circumstellar material. Ionic species and free radicals, produced by these processes, can lead
to the formation of new organic molecules. In this work we present the study of the photoionization and
photodissociation processes of the toluene molecule in gas phase using synchrotron radiation at soft X-ray
spectral regions and time of flight mass spectrometry. Mass spectra of ionic fragments were recorded at energies around C1s resonance (285 eV). The production of ions from the toluene were quantified, indicating
that C6 H5 CH3 is more efficiently fragmented by soft X-ray than by UV radiation, where 30% of the ionized
molecule survive to UV dissociation while only about 3% resist to X-rays. Partial ion yields of H+ and small
+
hydrocarbons such as C2 H+ , C3 H+
2 and C3 H3 are determined. Absolute photoionization and dissociative
photoionization cross sections have also been determined. From these values the ionization rate, destruction rate and half-life of methyl benzene molecule were also obtained for the X-ray photon fluxes in CRL 618.
For example, this molecule survives about 2 ⇥ 103 years at a distance of 595 AU from the central star.
B
1
2
[email protected]
Universidade Federal do Rio de Janeiro
Universidade Federal do ABC
96
Short Talks
ISM
ISM -1
Gas, dust and star formation in the infrared dust bubble S 24
Cappa, C. E.B1,2 ; Vasquez, J.1,2 ; Firpo, V.3 ; Duronea, N. U.4 ; Romero, G. A.2 ; Rubio, M.4
We analyze the interstellar medium in which the infrared dust bubble S 24 is evolving. Based on observations
of the 12 CO(2-1), 12 CO(3-2), 13 CO(2-1), and 13 CO(3-2) lines, and continuum at 870 µm obtained with the
Atacama Pathfinder Experiment (APEX) located in the north of Chile, and Herschel images at 70, 160, 250,
350 y 500 µm, we identified a gas and dust shell that surrounds the bubble showing active star formation. We
estimate the main physical parameters of the gas and dust and compare our results with other dust bubbles
in our Galaxy.
B
1
2
3
4
[email protected]
Facultad de Cs. Astronómicas y Geofı́sicas, UNLP, Argentina
Instituto Argentino de Radioastronomı́a, CONICET, Argentina
Universidad de La Serena, Chile
Universidad de Chile, Chile
97
ISM
Short Talks
ISM -2
The deceleration of nebular shells in evolved planetary nebulae
Margarita PereyraB1 ; Michael G. Richer1 ; José Alberto López1
We have selected a group of 100 evolved planetary nebulae (PNe) and study their kinematics based upon
spatially-resolved, long-slit, echelle spectroscopy. The data have been drawn from the San Pedro Mártir
Kinematic Catalogue of PNe (López et al. 2012). The aim is to characterize in detail the global kinematics
of PNe at advanced stages of evolution with the largest sample of homogenous data used to date for this
purpose. The results reveal two groups that share kinematics, morphology, and photo-ionization characteristics of the nebular shell and central star luminosities at the different late stages under study.The typical flow
velocities we measure are usually larger than seen in earlier evolutionary stages, with the largest velocities
occurring in objects with very weak or absent [N II]
6584 line emission, by all indications the least evolved
objects in our sample. The most evolved objects expand more slowly. This apparent deceleration during the
final stage of PNe evolution is predicted by hydrodynamical models, but other explanations are also possible.
These results provide a template for comparison with the predictions of theoretical models.
B
1
[email protected]
Instituto de Astronomı́a de la UNAM
98
Short Talks
ISM
ISM -2
The Carbon Content in Galactic Ring Nebulae: CNO Nucleosynthesis in Massive Stars
A. Mesa-DelgadoB1 ; J. Garcı́a-Rojas2 ; C. Esteban2 ; F. Bresolin3 ; C. Morisset4
Ring nebulae are interstellar bubbles of ionized gas that have swept-up the surrounding interstellar medium
(ISM) after mass loss episodes experienced by their progenitors. As such, they are valuable probes of the
chemical enrichment of the ISM by massive stars. In the last 50 years, the study of their chemical composition has been based on the analysis of optical data, which have mainly informed us about elements such
as He, N, O, and Ne. Carbon abundances, however, have been historically difficult to obtain. In this talk, we
will present the first determinations of C abundances based on the faint recombination line CII 4267 Å from
the analysis of the two brightest and nearest Galactic ring nebulae (NGC6888 and NGC7635). These crucial
results represent the first contraints on C abundances, providing long-awaited information on the action of
the CNO cycle that controls the nucleosynthesis processes in massive stars, and on the role of these in the
origin of carbon in the Universe.
B
1
2
3
4
[email protected]
Pontificia Universidad Católica de Chile
Instituto de Astrofı́sica de Canarias
Institute for Astronomy, University of Hawaii
Instituto de Astronomı́a, Universidad Nacional Autonoma de México
99
ISM
Short Talks
ISM -2
Ionization Correction Factors in Planetary Nebulae
Delgado Inglada, G.B1 ; Morisset, C.1 ; Stasinska, G.2
Element abundances in planetary nebulae (PNe) have been longly used as tracers of metallicity and also
as probes for stellar nucleosynthesis. In general, not all the ions present in the nebulae are observed, and
thus, we need to use ionization correction factors (ICFs) to account for their contribution. Much work has
been done on improving ICFs, but the correction scheme suggested by Kingsburgh & Barlow (1994), based
on around ten unpublished models, is still the most adopted one in the literature. Moreover, it is known that
some of these ICFs do not correct properly for unobserved ions (such as for Ne or S).
We compute an extensive grid of ⇠15000 photoionization models using the c10.00 version of Cloudy code
(Ferland et al. 1998) in order to re-analyze this issue. The models cover a wide range of Tef f , L⇤ , Rin , and nH ,
and incoporate blackbodies and Rauch atmospheres as ionizing sources. We calculate constant and nonconstant density models as well as radiation- and matter-bounded models. Using this grid of models, we
explore new ICFs for PNe, and, what is more important, we quantify the uncertainties associated with the
ICFs. We also use a large sample of PNe from the literature with observational data to test our ICFs. I will
present here some of our results and I will compare them with those obtained from previous ICFs.
B
1
2
[email protected]
Institute of Astronomy, UNAM (Mexico)
Paris-Meudon Observatory (France)
100
Short Talks
ISM
ISM -2
Carbon and Oxygen Abundances from Recombination Lines in Low Metallicity HII
Regions
Esteban, C.B1,2 ; Garcı́a-Rojas, J.1,2 ; Carigi, L.3 ; Mesa-Delgado, A.4
We present results on the analysis of deep echelle spectrophometry obtained with large aperture telescopes
of several interesting low-metallicity HII regions where CII and OII recombination lines have been detected.
Firstly, we discuss recent results about the shape of the Galactic C and C/O radial gradients at and beyond the
photometric radius of the Milky Way. Secondly, we present results on several giant extragalactic HII regions
and HII galaxies. The data permit to study the behavior of the abundance discrepancy factor the difference
between abundance determinations based on recombination and collisionally excited lines
ratios and C enrichment in the low-metallicity regime.
B
1
2
3
4
[email protected]
Instituto de Astrofı́sica de Canarias
Departamento de Astrofı́sica, Universidad de La Laguna
Instituto de Astronomı́a, Universidad Nacional Autónoma de México
Departamento de Astronomı́a y Astrofı́sica, Pontificia Universidad Católica de Chile
101
and the C/O
ISM
Short Talks
ISM -2
The internal density structure of Giant HII Regions
H. O. CastañedaB1 ; H. E. Caicedo Ortiz2 ; J. Perez Oregón1
By measuring the local density of the ionized gas we study the internal structure of Giant HII Regions in the
galaxies NGC 6822 and M 33. The data shows the existence of density gradients in localized areas of these
objects. The result should to be taken into account in the calculation of the chemical abundances of gaseous
nebula. We discuss the different models for the distribution of the radial density of the objects.
B
1
2
[email protected]
Departamento de Fisica, Escuela Superior de Fı́sica y Matemáticas. Instituto Politénico Nacional, Mexico
Grupo de Ingenierı́a y Tecnologı́as Cuántica, Corporación Universitaria Autónoma del Cauca, Popayán, Colombia
102
Galaxies
GAL -1
The abundance of galaxies and dark matter halos in the ⇤CDM Universe
Abadi, M. G.B1
The ⇤CDM cosmological model is the current paradigm for structure formation in the Universe. A longstanding puzzle of this model concerns the striking difference between the shape of the galaxy stellar mass
function and the cold dark matter halo mass function on dwarf galaxy scales. Dwarf galaxies are much less
numerous than halos massive enough to host them, suggesting a complex non-linear relation between the
mass of a galaxy and that of its surrounding halo. This is usually reconciled by appealing to baryonic processes that drastically reduce the efficiency of galaxy formation in low-mass halos. Recent models require
that virtually no dwarf galaxies form in halos with virial mass below 1010 M . We use rotation curves of dwarf
galaxies compiled from the literature to explore whether their total enclosed mass is consistent with these
constraints. We find that almost one-half of the dwarfs in our sample, are at odds with this restriction: they
live in haloes with masses substantially below 101 0M . This result presents a challenge to the cosmological
model ⇤CDM. We use a cosmological simulation of the formation of the Local Group of Galaxies to identify
a mechanism that enables the removal of baryons from low-mass halos without appealing to feedback or
reionization. This mechanism may help to explain the scarcity of dwarf galaxies compared with the numerous low-mass halos expected in ⇤CDM and the large diversity of star formation histories and morphologies
characteristic of faint galaxies.
B
1
[email protected]
Observatorio Astrónomico, Universidad Nacional de Córdoba and IATE, CONICET-UNC
103
Galaxies
Short Talks
GAL -1
The Formation of dSph galaxies
Fellhauer, M.B1 ; Assmann, P.1,2 ; Wilkinson, M. I.3
Dwarf spheroidal (dSph) galaxies are considered the basic building blocks of the galaxy formation process in
the ⇤CDM (Lambda Cold Dark Matter) hierarchical cosmological model. These galaxies are believed to be
the most dark matter (DM) dominated systems known, have the lowest stellar content, and are poor in gas.
Many theories attempt to explain the formation of dSph galaxies resorting to the fact that these galaxies are
mainly found orbiting large galaxies or invoking other mechanisms of interactions. Here we show the full set
of simulation as an extension of our fiducial model, where we study the formation of classical dSph galaxies
in isolation by dissolving star clusters within the DM halo of the dwarf galaxy. In our parameter survey we
adopt cored and cusped DM halo profiles and consider different numbers of dissolving star clusters. We
investigate the dependency of observable quantities with different masses and scale-lengths of the DM halo
and different star formation efficiencies (SFE). We find that our proposed scenario explains many features
of the classical dSph galaxies of the Milky Way, like their morphology and their dynamics. We see trends
how the surface brightness and the scale-length of the luminous component vary with the parameters of
our simulations. We also identify how irregularities in their shape, i.e. clumpiness and ellipticity vary in
our simulations. In velocity space, we identify the parameters leading to flat velocity dispersions curves. We
recognize kinematically cold substructures in velocity space, named fossil remnants and stemming from our
unique initial conditions, which alter the expected results. These streaming motions are considered as a key
feature for future observation with high resolution to validate our scenario.
B
1
2
3
[email protected]
Departamento de Astronomia, Universidad de Concepcion, Chile
Departamento de Astronomia, Universidad de Chile, Chile
Department of Physics & Astronomy, University of Leicester, UK
104
Short Talks
Galaxies
GAL -1
Constraining Galaxy Evolution with Scaling Relations
de la Rosa, I. G.B1,2 ; Ferreras, I.3 ; Dominguez, H.4 ; Lopes, P. A. A.2
The non-linear scaling relation involving surface brightness and magnitude for Early Type Galaxies (ETGs)
shows a prominent turnover at MB ⇡ - 20.5. In a previous stellar population study, using SDSS spectra, we
have sustained the idea of the turnover as a fundamental feature of the scaling relations, separating ETGs
with different star formation histories. An ongoing study is presented in which similar scaling relations are
constructed for ETGs in clusters with redshifts ranging from 0.2 to 0.9. Data are taken from the deep HST
observations of the CLASH Survey, including 25 clusters measured in 16 broad bands from NUV to NIR.
The variation of the turnover position with redshift, which shows a mixed sensitivity to cosmic expansion,
surface-brightness-dimming and galaxy evolution, is used as a consistency test for cosmic and galaxy evolution.
B
1
2
3
4
[email protected]
Instituto de Astrofisica de Canarias, Spain
Observatorio do Valongo, Brasil
University College London, UK
Centro de Astrobiologia, Spain
105
Galaxies
Short Talks
GAL -1
How do Brightest Cluster and Group galaxies grow? Observations vs Models
Oliva-Altamirano, P.B1,2 ; Brough, S.2 ; Lidman, C.2 ; Couch, W.2 ; Taylor, E.3
Brightest Cluster Galaxies (BCGs) represent the most luminous systems known at present epochs. The extent
to which such extreme galaxies have acquired their particular properties from their privileged location at the
centres of clusters and/or their high density environment is of key astrophysical interest. Unfortunately,
the assembly history and evolution of these giant galaxies is still poorly understood. We have analyse the
growth of BCGs in the last 3.5 billion years using a large sample (1220 BCGs/BGG) from the Galaxy and Mass
Assembly Survey (GAMA), and compared our results with the Semi-Analytic Models (SAMs) of De Lucia &
Blaizot (2007) and Tonini et al. (2012). By comparing like-to-like clusters we find no significant growth
between redshift 0 and 0.3, whereas SAMs predict that BCGs have acquired 30% of their stellar mass over this
period of cosmic time. We also examine the position of the BCGs with respect to their Dark Matter Halo and
find that around 14% of the BCGs are not lying at the centre of the dark matter halo potential well and this
could be an indicator of recent cluster mergers. In a further analysis, we found that around 40% of the BCGs
harbor on-going star formation, with rates in a range 0-4 M per year, in agreement with the new recipes
used in Tonini et al. (2012). While BCGs might not be completely dormant, the fraction of their mass being
converted into new stars is still very low.
B
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3
[email protected]
Swinburne university of Technology
Australian Astronomical Observatory (AAO)
University of Melbourne
106
Short Talks
Galaxies
GAL -1
Quenching Star Formation Now and Then: Downsizing of the Mass Flux Density in the
Green Valley
Gonçalves, T. S.B1 ; Menéndez-Delmestre, K.1 ; Nogueira-Cavalcante, J. P.1 ; Martin, D. C.2 ; Lopes, P. A. A.1
The bimodality in galaxy properties has been observed at low and high redshift, with a clear distinction
between star-forming galaxies in the blue cloud and passively evolving objects in the red sequence. The
absence of galaxies with intermediate properties indicates that the quenching of star formation and subsequent transition between populations must happen rapidly. By using very deep spectroscopy with the
DEIMOS instrument at the Keck telescope we are able to infer the star formation histories of so-called “green
valley” galaxies at intermediate redshifts (z ⇠ 0.8), when the universe was half its current age. We measure
the stellar mass flux density of green valley galaxies transiting from the blue cloud to the red sequence and
find that this transition happens more rapidly in the past and that at z ⇠ 0.8 this process happens more
rapidly for more massive galaxies. This suggests a top-down scenario in which the massive end of the red
sequence forms first, representing another aspect of downsizing, with the mass flux density moving towards
smaller galaxies in recent times. It remains an open question, however, which physical mechanisms are responsible for quenching star formation and how they may be more efficient at z ⇠ 0.8 than at lower redshifts.
To tackle this we have recently initiated a project to detect the presence of bars at low and high redshift, and
correlate their strength with the quenching timescales. This will allow us to infer the influence of secular
evolution in galaxies at different epochs.
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1
2
[email protected]
Observatório do Valongo, Universidade Federal do Rio de Janeiro
California Institute of Technology
107
Galaxies
Short Talks
GAL -2
Evolution models for spiral and irregular galaxies
M. MolláB1 ; O. Cavichia; R. D. D. Costa
We will summarize our grid of chemical and spectro-photometrical models applied to spiral and irregular
galaxies. They have been calculated consistently by applying to the chemical evolution code from Molla
& Diaz (2005), updated with the most recent inputs (Mollá & Dı́az 2013). We will analyze the impact of
the new assumptions related with the infall rate law, the IMF and stellar yields, and new prescriptions to
form molecular clouds. Furthermore we will show the spectro-photometric information obtained when the
evolutionary synthesis models from POPSTAR (Mollá et al 2009, Martı́n-Manjon 2010, Garcı́a-Vargas et al.
2013) are applied to the resulting star formation and enrichment histories of this type of galaxies.
B
1
[email protected]
CIEMAT (Spain) and Universidade de Sao Paulo (Brazil)
108
Short Talks
Galaxies
GAL -2
Galaxy And Mass Assembly (GAMA): The connection between metals, specific SFR and
H I gas in galaxies: the Z-SSFR relation
Lara-Lopez, M. A.B1 ; Hopkins, A. M.1 ; GAMA team
We study the interplay between gas phase metallicity (Z), specific star formation rate (SSFR) and neutral
hydrogen gas (HI) for galaxies of different stellar masses. Our study uses spectroscopic data from Galaxy and
Mass Assembly (GAMA) and Sloan Digital Sky Survey (SDSS) star-forming galaxies, as well as HI detection
from the Arecibo Legacy Fast Arecibo L-band Feed Array (ALFALFA) and Galex Arecibo SDSS Survey (GASS)
public catalogues. We present a model based on the Z-SSFR relation that shows that at a given stellar mass,
depending on the amount of gas, galaxies will follow opposite behaviours. Low-mass galaxies with a large
amount of gas will show high SSFR and low metallicities, while low-mass galaxies with small amounts of gas
will show lower SSFR and high metallicities. In contrast, massive galaxies with a large amount of gas will
show moderate SSFR and high metallicities, while massive galaxies with small amounts of gas will show low
SSFR and low metallicities. Using ALFALFA and GASS counterparts, we find that the amount of gas is related
to those drastic differences in Z and SSFR for galaxies of a similar stellar mass. The results of this study were
publish recently in a ”letter to the editor” (Lara-Lopez, M. A. et al. 2013, MNRAS, 433, L35)
B
1
[email protected]
Australian Astronomical Observatory, PO Box 915, North Ryde, NSW 1670, Australia
109
Galaxies
Short Talks
GAL -2
Evolution of the Mass-Metallicity relations in passive and star-forming galaxies from
SPH-cosmological simulations
A. D. RomeoB1 ; J. Sommer-Larsen2 ; N. R. Napolitano3 ; V. Antonuccio-Delogu1
We present results from SPH-cosmological simulations, including self-consistent modelling of SN feedback
and chemical evolution, of galaxies belonging to two clusters and twelve groups. We reproduce the mass–
metallicity (ZM) relation of galaxies classified in two samples according to their star-forming activity, as
parametrized by their sSFR, across a redshift range up to z = 2.
The overall ZM relation for the composite population evolves according to a redshift-dependent quadratic
functional form that is consistent with other empirical estimates, provided that the highest mass bin of the
BCGs is excluded.
Its slope shows irrelevant evolution in the passive sample, being steeper in groups than in clusters. However, the sub-sample of high-mass passive galaxies only is characterized by a steep increase of the slope with
redshift, from which it can be inferred that the bulk of the slope evolution of the ZM relation is driven by
the more massive passive objects. The scatter of the passive sample is dominated by low-mass galaxies at all
redshifts and keeps constant over cosmic times. The mean metallicity is highest in cluster cores and lowest
in normal groups, following the same environmental sequence as that previously found in the Red Sequence
building.
The ZM relation for the star-forming sample reveals an increasing scatter with redshift, indicating that it
is still being built at early epochs. The star-forming galaxies make up a tight sequence in the SFR-M⇤ plane
at high redshift, whose scatter increases with time alongside with the consolidation of the passive sequence.
We also confirm the anti-correlation between sSFR and stellar mass, pointing at a key role of the former
in determining the galaxy downsizing, as the most significant means of diagnostics of the star formation
efficiency. Likewise, an anti-correlation between sSFR and metallicity can be established for the star-forming
galaxies, while on the contrary more active galaxies in terms of simple SFR are also metal-richer.
Finally the [O/Fe] abundance ratio is presented too: we report a strong increasing evolution with redshift at given mass, especially at z > 1. The expected increasing trend with mass is recovered when only
considering the more massive galaxies.
We discuss these results in terms of the mechanisms driving the evolution within the high- and lowmass regimes at different epochs: mergers, feedback-driven outflows and the intrinsic variation of the star
formation efficiency.
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1
2
3
[email protected]
INAF-OA Catania, Italia
Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Danmark
INAF-OA Capodimonte, Napoli, Italia
110
Short Talks
Galaxies
GAL -2
The formation of stellar haloes of massive Spirals in hierarchical scenario
Patricia B. TisseraB1,2 ; Timothy C. Beers4 ; Daniela Carollo5 ; Cecilia Scannapieco3
We investigate the chemical and kinematic properties of the diffuse stellar haloes of six simulated Milky
Way-like galaxies from the Aquarius Project. Binding energy criteria are adopted to defined two dynamically distinct stellar populations: the diffuse inner and outer haloes, which comprise different stellar subpopulations with particular chemical and kinematic characteristics. Our simulated inner- and outer-halo
stellar populations have received contributions from debris stars (formed in sub-galactic systems while they
were outside the virial radius of the main progenitor galaxies) and endo-debris stars (those formed in gasrich sub-galactic systems inside the dark matter haloes). The inner haloes possess an additional contribution
from disc-heated stars in the range 3
30%, with a mean of ⇠ 20% . Disc-heated stars can exhibit signatures
of kinematical support, in particular among the youngest ones. Endo-debris plus disc-heated stars define
the so-called insitu stellar populations. In both the inner- and outer-halo stellar populations, we detect
contributions from stars with moderate to low [alpha/Fe] ratios, mainly associated with the endo-debris or
disc-heated sub-populations. The observed abundance gradients in the inner-halo regions are influenced
by both the level of chemical enrichment and the relative contributions from each stellar sub-population.
Steeper abundance gradients in the inner-halo regions are related to contributions from the disc-heated and
endo-debris stars, which tend to be found at lower binding energies than debris stars. In the case of the
outer-halo regions, although [Fe/H] gradients are relatively mild, the steeper profiles arise primarily due to
contributions from stars formed in more massive satellites, which sink farther into the main halo system,
and tend to have higher levels of chemical enrichment and lower energies. Our results show how the abundances of the stars in the stellar haloes vary with radius up to the virial radius and how the characteristics
of the metallicity distributions can be linked to the history of assembly within in hierarchical clustering scenario
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1
2
3
4
5
[email protected]
Consejo Nacional de Investigaciones Cientı́ficas y Técnicas, CONICET, Argentina
Instituto de Astronomı́a y Fı́sica del Espacio, Casilla de Correos 67, Suc. 28, 1428, Buenos Aires, Argentina
Max-Planck Institute for Astrophysics, Karl-Schwarzchild Str. 1, D85748, Garching, Germany
National Optical Astronomy Observatory, Tucson, 85719, USA
Macquarie University, Dept. Physics & Astronomy, Sydney, 2109 NSW, Australia
111
Galaxies
Short Talks
GAL -2
The effects of dark matter halo on the mass loss process in dwarf galaxies: results from
3D hydrodynamical simulations
Lanfranchi, G. A.B1 ; Ruiz, L. O.1 ; Falceta-Goncalves, D.2 ; Caproni, A.1
Theoretical ⇤ CDM cosmological models predict a much larger number of low mass dark matter haloes than
has been observed in the Local Group of galaxies. One possible explanation is the increased difficulty of detecting these haloes if most of the visible matter is lost at early evolutionary phases through galactic winds.
In this work we study the current models of triggering galactic winds in dwarf spheroidal galaxies (dSph)
from supernovae, and study, based on 3D hydrodynamic numerical simulations, the correlation of the mass
loss rates and important physical parameters as the dark matter halo mass and the star formation rate. We
find that the existence of winds is ubiquitous, independent on the gravitational potential, as would be expected. This because our simulations revealed that the Rayleigh-Taylor Instability (RTI) may play a major
role on pushing matter out of these systems, even for very massive haloes. However, as already reported in
previous works we have found a correlation between the mass loss rate and both the halo mass and the rate
of supernovae. Besides, the epoch in which most of the baryon galactic matter is removed from the galaxy
varies depends on those quantities. This result, combined to the importance of the RTI in each model, may
change our understanding about the chemical evolution of dwarf galaxies, as well as in the heavy element
contamination of the intergalactic medium at high redshifts.
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1
2
[email protected]
NAT - Universidade Cruzeiro do Sul, SP-Brasil
EACH/USP, SP-Brasil
112
Short Talks
Galaxies
GAL -3
TP-AGB stars and population synthesis models
Gustavo BruzualB1
Using updated evolutionary tracks for TP-AGB stars from the Padova Group we explore by means of Montecarlo Simulations to what extent the Luminosity Functions and color distributions of TP-AGB stars in the
LMC and SMC observed by the SAGE collaboration can be reproduced with these tracks. We compute as well
the gas and dust production rate by TP-AGB stars in these galaxies, and derive the amount of gas and dust
expelled by these stars during the past few Gyr. Detailed comparison with observations allow us to quantify the uncertainties introduced in population synthesis models by the use of these evolutionary tracks. We
show that current models provide a better description of nature than previous versions.
B
1
[email protected]
CRyA, UNAM, Campus Morelia, Mexico
113
Galaxies
Short Talks
GAL -3
Spectral Synthesis of Star-forming Galaxies in the Near-Infrared
Martins, L. P.B1 ; Rodrı́guez-Ardila, A.2 ; Diniz, S.1,3 ; Riffel, R.3 ; de Souza, R.4
The near-infrared spectral region is becoming a very useful wavelength range to detect and quantify the stellar population of galaxies. Models are developing to predict the contribution of TP-AGB stars, that should
dominate the NIR spectra of populations 0.3 to 2 Gyr old. When present in a given stellar population, these
stars leave unique signatures that can be used to detect them unambiguously. However, these models have
to be tested in a homogeneous database of star-forming galaxies, to check if the results are consistent with
what is found from different wavelength ranges. In this work we performed stellar population synthesis on
the nuclear and extended regions of 23 star-forming galaxies to understand how the star-formation tracers
in the near-infrared can be used in practice. The stellar population synthesis shows that for the galaxies with
strong emission in the NIR, there is an important fraction of young/intermediate population contributing to
the spectra, which is probably the ionization source in these galaxies. Galaxies that had no emission lines
measured in the NIR were found to have older average ages and less contribution of young populations.
Although the stellar population synthesis method proved to be very effective to find the young ionizing population in these galaxies, no clear correlation between these results and the NIR spectral indexes were found.
Thus, we believe that, in practice, the use of this indexes is still very limited due to observational limitations.
B
1
2
3
4
[email protected]
NAT - Universidade Cruzeiro do Sul
Laboratório Nacional de Astrofı́sica
Universidade Federal do Rio Grande do Sul
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas - USP
114
Short Talks
Galaxies
GAL -3
A new class of galaxies (?): ultra-compact dwarfs
Mieske, S.B1
I propose to give a review on ultra-compact dwarf galaxies (UCDs), a new class of stellar systems defining
the interface between star clusters and dwarf galaxies. UCDs are believed to be either the most massive star
clusters in the universe, tidally truncated galaxies, or, both. After a brief overall summary, I will focus in
particular on two aspects. 1. The specific frequencies of UCDs - a recently introduced quantity that allows
to test whether the luminosity distribution of UCDs follows the bright tail of the globular cluster luminosity
function. Can all UCDs be explained as bright star clusters? 2. The elevated dynamical M/L ratios of UCDs.
Are they due to highly clustered dark matter, a variation of the IMF, or maybe, due to massive central black
holes that would be fossil relicts of UCD progenitor galaxies?
B
1
[email protected]
ESO Chile
115
Galaxies
Short Talks
GAL -3
Andromeda’s interplay with its dwarf companions
Gonçalves, D. R.B1 ; Carneiro, C. M.1 ; Magrini, L.2 ; Teodorescu, A. M.3,4
Dwarf galaxies are the most numerous galactic systems in the Universe, mostly found in galaxy groups.
Dwarfs in the Local Group (LG) are excellent laboratories in which to study galaxy evolution. Among the
bright resolved stars in the LG dwarf galaxies, the strong emission line feature in the spectrum of planetary
nebulae (PNe) allow us to study the late evolutionary stages of stars with low and intermediate masses, as
well as the star formation history and the chemical evolution of the galaxy, within the age range of 1-10 Gyr.
In a series of previous studies we have investigated the chemical properties of the emission-line populations of LG dwarf galaxies, observing HII regions and PNe in galaxies presently forming stars, such as dwarf
Irregulars (dirrs) and of PNe in quiescent galaxies, such as dwarf spheroidals (dSphs).
The major aims of our studies can be summarised as follows. i) Deriving the chemical composition of
dwarf galaxies from PNe (and HII regions, whenever possible), and setting constraints to galaxy formation
and evolution, and giving us the unique opportunity to determine the chemical composition of the ISM in
different epochs, as at present and at the time of the formation of the PN progenitors. ii) Studying the stellar nucleosynthesis of low- and intermediate-mass stars in different conditions, and in different metallicity
environments. iii) Deriving, in a homogeneous way, the metallicity traced, e.g., by the oxygen abundance, in
both dIrrs and dSphs, allowing to derive the mass-metallicity relationship for all dwarf galaxies. Ultimately,
fully disentangle the possible differences in this relation, claimed in the past, for star-forming and non starforming galaxies.
In this framework, here we present GMOS spectroscopic observations of the PN population in the dwarf
galaxy NGC 205, the brightest early-type dwarf satellite of the Andromeda galaxy (M 31). Among the low surface brightness galaxies in the LG, this is of particular importance due to its interesting star formation history, and also to several indications of a tidal encounter with its massive companion (M 31), being the galaxy
located at the shortest projected distance of the three more massive dwarf companions of Andromeda.
In this contribution, we discuss –in terms of the three main aspects above– the new observations of a
sample of 37 candidate PNe, 24 of them resulted to be true PNe, one is a symbiotic system, and the remaining
ones are stars.
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1
2
3
4
[email protected]
Observatório do Valongo - Universidade Federal do Rio de Janeiro, Brazil
INAF - Osservatorio Astrofisico di Arcetri, Florence, Italy
Consiglio Nazionale delle Ricerche, Pisa, Italy
Institute for Astronomy, University of Hawaii, USA
116
Short Talks
Galaxies
GAL -3
Assessment of the SFH retrieved from synthetic u’g’r’i’z’ photometry of galaxies
Mejı́a, A. J.B1 ; Magris, G.1
In recent decades the photometric data exceeds enormously the spectroscopic data. The Sloan Digital Sky
Survey (SDSS), for instance, puts to disposition of the astronomical community high quality photometric
data, covering a sky area considerably large and reaching depths without precedents. This work aims to assess the physical parameters retrieved from a photometric sample of synthetic galaxies using the DINBAS
algorithm. In order to achieve this objetive this steps were followed: (1) the construction of a library of synthetic galaxies with observational properties similars to that of the galaxies observed by the SDSS; (2) the assessment of the SFH retrieved from the photometry by comparing with the already known input SFH; (3) the
comparison between the SFH retrieved from the spectroscopy and that retrieved from the photometry using
DINBAS. It was found that mass and age were degenerated when the SFH was retrieved from the u’g’r’i’z’
photometry employing DINBAS. In all the cases, the spectroscopy was more accurate than photometry, with
uncertainties within ⇠ 20% and ⇠ 70%, respectively.
B
1
[email protected]
Centro de Investigaciones de Astronomı́a
117
Galaxies
Short Talks
GAL -4
First spatially-resolved observations of ionized gas in submillimeter-selected
high-redshift starbursts
Menéndez-Delmestre, K.B1 ; Blain, A. W.2 ; Swinbank, M.3 ; Smail, I.3 ; Ivison, R. J. 4 ; Chapman, S. C.5 ; Gonçalves, T. S.1
We present the first spatially-resolved observations of the H-alpha emission in z ⇠ 2 submillimeter-selected
galaxies (SMGs) using the Keck OH-Suppressing Infrared Imaging Spectrograph (OSIRIS) with Laser Guide
Star Adaptive Optics (LGS-AO). The kpc-scale spatially-resolved view into these complex systems – up to ten
times that achieved with previous seeing-limited studies – allows us to explicitly distinguish between compact AGN-dominated regions of broad H-alpha emission (FWHM > 1000 km/s) from more extended regions
exhibiting narrow H-alpha emission (FWHM < 500 km/s) and thus likely dominated by star formation activity. We observe that the distribution of star formation in these objects is characterized by multiple Halphabright kpc-scaled clumps, each presenting high star-formation rate surface densities, with values similar to
that of local extreme sources, such as circumnuclear starbursts and luminous infrared galaxies. However, in
contrast to these local environments, SMGs appear to be undergoing such intense activity on significantly
larger spatial scales as revealed by extended H-alpha emission over 4-16 kpc. The estimated clump masses
and specific star-formation rates set SMGs off the main-sequence of star-forming objects at z ⇠ 2. The Halpha kinematics reveal no evidence of ordered global motion as would be found in a disk, but rather large
velocity offsets (⇠few x 100 km/s) between the distinct clumps. Assuming that the broad H-alpha emission
identifies a super-massive black hole likely at the dynamical center of system, we interpret both the velocity
offsets between the observed clumps and their asymmetric distribution around the broad H-alpha region as
an indication that these are not likely to reside in a regular potential well structure. Although a clumpy disk
structure has been suggested in other populations of star-forming galaxies at similar redshifts, the merger
interpretation is likely the most accurate scenario for the SMGs in our sample. However, the final test of
whether an underlying disk structure is present will come from detailed studies of the cold molecular gas at
the high spatial resolutions possible with ALMA.
B
1
2
3
4
5
[email protected]
Valongo Observatory of the Federal University of Rio de Janeiro, Brazil
University of Leicester, UK
Institute for Computational Cosmology, Durham University, UK
University of Edinburgh/Royal Observatory
Institute of Astronomy, Cambridge, UK
118
Short Talks
Galaxies
GAL -4
Comparing galaxy populations in compact and loose groups of galaxies
Martinez, H. J.B1 ; Coenda, V.1 ; Muriel, H.1
We compare the properties of galaxies in compact groups, loose groups, and the field to deepen our understanding of the physical mechanisms acting upon galaxy evolution in different environments.
We select samples of galaxies in compact groups identified by McConnachie et al. (2009), and in loose
groups taken from Zandivarez & Martı́nez (2011). We compare properties of the galaxy populations in these
different environments: absolute magnitude, colour, size, surface brightness, stellar mass, and concentration and morphological information from the Galaxy Zoo. We also study the fraction of red and early-type
galaxies, the luminosity function, the colour-luminosity, and luminosity-size relations. Particularly, we analyse the fraction of the group’s total luminosity contained in the brightest group galaxy (BCG) and the difference in luminosity between the BCG and the second ranked galaxy.
We find that the population of galaxies in compact groups differ from that of loose groups and the field.
The fraction of red and early-type galaxies is larger in compact groups. Galaxies in compact groups are, on
average, systematically smaller in size, more concentrated, and have higher surface brightnesses than galaxies in the field and in loose groups. At a fixed absolute magnitude, or fixed surface brightness, galaxies in
compact groups are smaller in size. In addition, BCGs in compact groups are systematically more concentrated and have larger surface brightness than their counterparts in both, high and low mass loose groups.
Our results show that BCGs in compact groups are, on average, brighter, more massive, larger, redder and
more frequently classified as elliptical. We find that, in compact groups, the BCG contains a larger fraction
of the system’s total luminosity and differ more in absolute magnitude with the second ranked galaxy.
The physical mechanisms that transform galaxies into earlier types could be more effective within compact groups, owing to the typically high densities and small velocity dispersions of these environments,
which could explain the large fraction of red and early-type galaxies we found in compact groups. Galaxies inhabiting compact groups have undergone a major transformation compared to galaxies that inhabit
loose groups.
B
1
[email protected]
Instituto de Astronomia Teorica y Experimental, CONICET-Universidad Nacional de Cordoba, Argentina
119
Galaxies
Short Talks
GAL -4
CALIFA: The local extragalactic universe unveiled (survey status)
Rosales-Ortega, F. F.B1 ; Sánchez, S. F.2 ; CALIFA team
The Calar Alto Legacy Integral Field Area Survey (CALIFA) is observing a statistically well-defined sample of
⇠600 galaxies in the local universe using the PMAS/PPAK IFU, mounted on the Calar Alto 3.5 m telescope.
CALIFA has just published its first Data Release (DR1), prodivindg freely to the community fully reduced and
quality control tested datacubes of 100 objects in two spectral resolutions. This data will allow scientists
to produce maps for the different properties of galaxies, such as velocity, stellar ages or chemical composition, to mention just a few. We present the current survey status and the last scientific outcomes from the
collaboration.
B
1
2
[email protected]
Instituto Nacional de Astrofı́sica, Óptica y Electrónica, Mexico
Instituto de Astrofı́sica de Andalucı́a
120
Short Talks
Galaxies
GAL -4
Fireworks at the center of the Milky Way
João E. SteinerB1 ; Roberto B. Menezes1 ; Daniel Amorim de Oliveira1
The central parsec of the Milky Way is a very special region of our Galaxy; it contains the supermassive black
hole associated with Sgr A* as well as a significant number of early-type stars and a complex structure of
streamers of neutral and ionized gas, within two parsec from the centre, representing a unique laboratory.
We report the identification of a high velocity compact nebular filament 2.2 arcsec south of Sgr A*. The
structure extends over ⇠1 arcsec and presents a strong velocity gradient of ⇠200 km s
1
arcsec
1
. The peak of
maximum emission, seen in [Fe III] and He I lines, is located at d↵ = +0.20±0.06 arcsec and d =
2.20±0.06
arcsec with respect to Sgr A*. This position is near the star IRS 33N. The velocity at the emission peak is Vr =
-267 km s
1
. The filament has a position angle of PA = 115o ± 10o , similar to that of the Bar and of the Eastern
Arm at that position. The peak position is located 0.7 arcsec north of the binary X-ray and radio transient
CXOGX J174540.0-290031, a low-mass X-ray binary (LMXB) with an orbital period of 7.9 h. The [Fe III] line
emission is strong in the filament and its vicinity. These lines are probably produced by shock heating but
we cannot exclude some X-ray photoionization from the LMXB. Although we cannot rule out the idea of a
compact nebular jet, we interpret this filament as a possible shock between the Northern and the Eastern
Arm or between the Northern Arm and the mini-spiral ‘Bar’.
B
1
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas - USP
121
Galaxies
Short Talks
GAL -4
Mapping dust-obscured light in CALIFA galaxies
Vale Asari, N.B1, 2 ; Wild, V.3 ; Kennicutt, R.2 ; Cid Fernandes, R.1
The Calar Alto Legacy Integral Field Area (CALIFA) survey is the first and largest survey of its kind, aiming to
obtain optical datacubes for 600 nearby (z ⇠ 0.01) galaxies. Over 300 objects have already been observed.
The spatial and spectral resolutions in CALIFA, combined with its sample size, offer unprecedented good
quality data to study spatially resolved dust properties. This work focus on how dust is mapped by the ionized gas. By carefully removing the underlying stellar population, we measure the emission-line Balmer
decrement (H↵/H ) in different regions in galaxies, separating HII complexes from diffuse emission. Preliminary results show that the effective dust attenuation measured on an integrated spectrum is underestimated with respect to the effective attenuation on HII regions. This implies that star formation indicators
based on optical and UV data should be used with care and may need to be corrected by differential dust
attenuation.
B
1
2
3
[email protected]
Departamento de Fisica, UFSC, Brazil
Institute of Astronomy, University of Cambridge, UK
School of Physics and Astronomy, University of St Andrews, UK
122
Short Talks
Galaxies
VVV-1
The wide view of the Bulge from the VVV survey
B1
Oscar A. Gonzalez
; Dante Minniti2,7 ; Philip Lucas3 ; Marina Rejkuba1 ; Manuela Zoccali2,7 ; Elena Valenti1 ; Roberto
Saito2,4,7,9 ; Jim Emerson5 ; Ignacio Toledo6 ; Maren Hempel2,7
The first year of observations of the Galactic bulge in the Vista Variables in the Via lacteal (VVV) ESO Public
Survey, with the VISTA telescope, have yielded a deep, near-infrared, multi-colour (Z,Y,J,H,Ks) photometric coverage of over 320 square degrees. Results based on this impressive dataset are presented, showing
the global properties of the bulge in order to investigate its place in the general context of galaxy bulges.
Extinction has been mapped using the magnitude and colour of the red clump, revealing a large amount
small-scale structure. This extinction map has been used to de-redden the VVV stellar photometry to study
the complicated bulge morphology from the absolute magnitude of the red clump and to derive photometric metallicities from the color of red giant branch stars. These results provide unique constrains for modern
Galaxy formation models..
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1
2
3
4
5
6
7
9
[email protected]
ESO
Departamento Astronomia y Astrofisica, Pontificia Universidad Catolica de Chile
Center for Astrophysics Research, University of Hertfordshire
Departamento de Fisica y Astronomia, Universidad de Valparaiso
School of Mathematical Sciences, Queen Mary University of London
ALMA OSF
The Milky Way Milennium Nucleus
Universidade Federal de Sergipe, Departamento de Fı́sica
123
Galaxies
Short Talks
GAL -5
The role of the corotation resonance in the secular evolution of disks of spiral galaxies
Jacques R. D. LepineB1 ; S. Scarano Jr.2 ; D. A. Barros1 ; T. C. Junqueira1 ; W. S. Dias3 ; S. Andrievsky4
The corotation resonance plays an important role in the evolution of the disks of spiral galaxies, and in particular, of our Galaxy. Its effect on the chemical abundance gradients is even a tool to estimate the age of
the present spiral arm structure, which we find to be long-lived, contrary to a recent common belief. The
metallicity gradients usually decrease in the inner regions and become flat or rising at larger radii. In several
galaxies, including the Milky Way, one observes not only a change in the slope of the abundance gradient,
but also an abrupt step in metallicity at corotation. This step is because the corotation resonance separates
the disk of a galaxy in two regions (inside corotation and outside corotation) which are isolated one from the
other, so that the two sides evolve in an independent way. The barrier between the two regions is the result
of the flow of gas in opposite directions on the two sides and by the ring-shaped void of gas observed at corotation. We investigated a sample of galaxies, which have a known corotation radius, and for which there are
measurements of abundance gradients of Oxygen available in the literature. A very good correlation is found
between corotation radii and the radii at which there is a break in the slope of the gradients. Besides this, an
independent effect of corotation is a minimum of star formation associated with the minimum velocity at
which the interstellar gas feeds the spiral arms (seen as potential wells and star-formation machines). Still
another effect is the scattering of stars by the resonance, which causes their migration to different galactic
radii.
B
1
2
3
4
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, Universidade de São Paulo, São Paulo, SP, Brazil
Universidade Federal de Sergipe - Departamento de Fı́sica DFI/CCET, São Cristovão, SE, Brazil
Instituto de Fı́sica e Quı́mica, Universidade Federal de Itajubá, Itajubá MG, Brazil
Department of Astronomy and Astronomical Observatory, Odessa National University, Odessa, Ukraine
124
Short Talks
Galaxies
GAL -5
Bar and spiral arms dynamics in numerical simulations
Ivânio PuerariB1 ; Irapuan Rodrigues de Oliveira Filho2
We present the results of SPH simulations with multi-million particles models. The models were constructed
with an exponential disk, Spitzer’s isothermal sheet in the vertical direction and a NFW halo. In models having a bulge, a spherical Hernquist profile was used. The models were evolved for approximately 5 Gyears
using Gadget 2. We present 1D and 2D Fourier analysis to quantify bar characteristics as length, strength,
and pattern speeds. Fourier 2D analysis is also applied to show the effects of the swing amplification mechanism. Indeed, the density waves begin to be amplified as tightly wound leading spirals and unwound to open
leading structures. Afterwards, the waves wound into trailing patterns, reach their maximum amplitude and
finally, fade away as tightly wound trailing spirals. The timescale for each wave packet is of the order of some
108 years.
B
1
2
[email protected]
INAOE, Mexico
Universidade do Vale do Paraı́ba, Brazil
125
Galaxies
Short Talks
GAL -5
Pitch Angle Restrictions in Normal Spiral Galaxies Based on Ordered and Chaotic
Orbital Behavior
Perez-Viilegas, A.B1 ; Pichardo, B.2
We built a family of non-axisymmetric potential models for normal non-barred or weakly-barred spiral
galaxies as defined in the simplest classification of galaxies: the Hubble sequence. For this purpose a threedimensional self-gravitating model for spiral arms PERLAS is superimposed to the galactic axisymmetric
potentials. We analyze the stellar dynamics varying only the pitch angle of the spiral arms. Self-consistency
is indirectly tested through periodic orbital analysis, and through density response studies for each morphological type. In a first limit, based on ordered behavior, periodic orbits studies show that for pitch angles
up to approximately 15 deg, 18 deg, and 20 deg for Sa, Sb and Sc galaxies, respectively, the density response
supports the spiral arms potential, a requisite for the existence of a long-lasting large-scale spiral structure.
Beyond those limits, the density response tends to ”avoid” the potential imposed by maintaining lower pitch
angles in the density response; in that case the spiral arms may be explained as transient features rather
than long-lasting large-scale structures. In a second limit, from a phase space orbital study based on chaotic
behavior, we found that for pitch angles larger than ⇠ 30 deg, ⇠ 40 deg and ⇠ 50 deg for Sa, Sb, and Sc galax-
ies, respectively, chaotic orbits dominate all phase space prograde region that surrounds the periodic orbits
sculpting the spiral arms and even destroying them. This result seems to be in good agreement with observations of pitch angles in typical isolated normal spiral galaxies.
B
1
2
[email protected]
Centro de Radioastronomia y Astrofisica, UNAM
Instituto de Astronomı́a, UNAM
126
Short Talks
Galaxies
GAL -5
Probing the assembly of galaxy groups with intragroup light
Eigenthaler, P.B1
Compact groups of galaxies are an environment where the evolution of galaxies occurs under extreme conditions due to the high spatial volume density of member galaxies and their low relative velocities implying
that galaxy interactions should be frequent and efficient. N-Body simulations predict that compact groups
should collapse in a small fraction of the Hubble time to a single elliptical, but retaining the extended Xray halo, forming so called fossil galaxy groups. Considering that fossil groups are the remnants of mergers
in compact groups, the merger history of the progenitor group is expected to be imprinted in todays fossil groups. In recent years, a diffuse component of optical intragroup light (IGL) was detected in Hickson
compact groups. A correlation between the structural properties of the IGL and indicators of dynamical evolution in compact groups like crossing time and the fraction of early-type galaxies has been found. Therefore,
the IGL can be taken as a new tool to investigate the evolutionary stage and interaction history of compact
groups. If fossil galaxy groups are indeed merged compact groups that assembled early in the universe, the
observed correlations suggest a prominent and relaxed IGL component in fossil groups. No IGL has been
detected so far in fossil groups. Once detected in these systems, its structure and kinematics will be a powerful diagnostic to study the evolutionary history of fossil groups. If fossil galaxy groups formed early, then
stars dispersed within the IGL should have had enough time to form a relaxed and virialised IGL component
tracing the dark matter halo of the host group. On the other hand, if the assembly of the central elliptical in
fossils just happened recently, then a highly structured IGL would be expected because of the large relaxation
timescales of such structures.
Addressing these topics, I will highlight ongoing plans to detect the diffuse IGL component in fossil
groups and present a kinematical study of the intragroup light in Hickson Compact Group 90 based on a
Multi-Slit-Imaging-Spectroscopy (MSIS) technique. In this approach, planetary nebulae dispersed in the
IGL are used as kinematical tracers via their characteristic [OIII] 5007Å line. The kinematic data will allow
us to better understand the nature and origin of the IGL in compact groups and reveal its overall dynamical
stage, virialised or unrelaxed. It is the first time that this technique is applied to the group environment.
B
[email protected]
Instituto de Astrofı́sica, Facultad de Fı́sica, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul,
Santiago, Chile
1
127
Galaxies
Short Talks
GAL -5
Backsplash Galaxies
Muriel, H.1 ; Coenda V.B1
We explore the properties of galaxies on the outskirts of clusters and their dependence on recent dynamical
history. Our aim is to know the real impact that the cluster core has on the evolution of galaxies. We analyze
the photometric and spectroscopic properties of more than 1000 galaxies on the outskirts of 90 clusters (1 <
r/rvir < 2) in the redshift range 0.05 < z < 0.10. Using the radial velocity of galaxies we selected high and low
velocity subsamples. According to theoretical predictions, a significant fraction of the first subsample should
be backsplash galaxies (BS), that is, objects that have already orbited near the cluster center. A significant
proportion of the sample of galaxies of high relative velocity (HV) seems to be composed of in-falling objects.
Our results show that, BS galaxies are on average redder, less luminous and smaller than HV. At fixed stellar
mass, we found that late-type galaxies in the BS sample are systematically older and have formed fewer
stars during the last 3 Gyrs than galaxies in the HV sample. This is consistent with models that assume that
the central regions of clusters are effective in quenching the star formation by means of processes like ram
pressure stripping or strangulation. At fixed stellar mass, BS galaxies tend to have higher surface brightness
and smaller size than HV galaxies. These results may be related to dynamical processes which determine
that galaxies that have orbited the central regions of clusters are more likely to suffer tidal effects, such as the
loss of part of their mass as well as a re-distribution of matter towards more compact configurations. Finally,
we found a higher fraction of ET galaxies in the BS sample, supporting the idea that the central region of
clusters of galaxies can contribute to the transformation of morphological types towards earlier types.
B
1
[email protected]
IATE-OAC, Córdoba, Argentina
128
Short Talks
Galaxies
GAL -6
BUDHIES: a Blind Ultra Deep HI Environmental Survey
Yara L. JafféB1 ; Bianca M. Poggianti; M. A. Verheijen; Jacqueline H. van Gorkom
I will present recent results from the Blind Ultra Deep HI Environmental Survey (BUDHIES), that has detected over 150 galaxies at z ⇠ 0.2 with the Westerbork Synthesis Radio Telescope. Our multi-wavelength
study is the first where optical properties and HI content are combined at a redshift where evolutionary ef-
fects begin to show. I will discuss the link between the environment, HI content, morphology, stellar mass
and star formation in galaxies at z ⇠ 0.2, and the importance of different physical mechanisms in the transformation of galaxies.
B
1
[email protected]
Universidad de Concepcion
129
Galaxies
Short Talks
GAL -6
Emission line imaging survey of the Abell 901/902 supercluster
Ana Chies-SantosB1 ; Bruno Rodriguez del Pino1 ; Alfonso Aragón-Salamanca1 ; Steven Bamford1 ; Meghan Grey1
It is widely debated whether galaxy evolution is more prone to internal or external effects. Trends to passive and/or more spheroidal populations in dense environments are widely observed and star-formation
rate and stellar age and AGN fraction all correlate with measurements of the local galaxy density. However,
in the hierarchical framework of galaxy formation the galaxies in the densest peaks start forming stars and
assembling mass earlier making stellar mass one of the key determinants of galaxy properties. Nonetheless
environmental effects are still very important and could be separated from the effect of internal galaxy properties. The Abell 901(a,b)/902 multiple cluster system at z ⇠ 0.165 is a unique laboratory for galaxy evolution.
Besides three main clusters it includes a few related groups. The field comprises a very broad range of galaxy
environments and masses at a single redshift. Therefore by observing this single region one is able to study
galaxy evolution decoupling environmental and stellar mass effects from redshift-related ones. We are currently undertaking a survey of the region with the OSIRIS tunable filter imager on the GRANTECAN. We have
targeted the H↵ and [NII] 6584 lines Together, these will provide the urgently needed star formation rate
and AGN diagnostics for a full census of such properties in this field. In this talk I will present the first results
of the survey on the high density regions A901a and A902 probing AGN and star formation.
B
1
Ana.Chies [email protected]
University of Nottingham, UK
130
Short Talks
Galaxies
GAL -6
The Next Generation Virgo Cluster Survey - Infrared (NGVS-IR)
Thomas H. PuziaB1 ; Roberto Munoz1 ; Ariane Lancçon2 ; NGVS collaboration
I will present a progress report of the most advanced near-UV/optical/near-IR photometric survey of the
Virgo galaxy cluster that in the optical covers a total area of 104 square degrees from its core to its virial radius. The near-IR follow-up program (NGVS-IR) currently covers 20 square degrees around M87 and M49
and is being continuously expanded. After an overview of some technical aspects, I will discuss several primary science topics of the NGVS+NGVS-IR survey, in particular focussing on stellar population diagnostics
in galaxies and star clusters. Combining near-UV, optical and near-IR data, we build the uiK color-color diagram of the pilot survey area. This displays significantly clearer substructure in the object distribution than
the gzK diagram – the NGVS+NGVS-IR-equivalent of the classic BzK diagram, which is widely used in cosmological surveys. Most remarkably, the uiK diagram allows for a very clean color-based selection of globular
clusters in Virgo.
B
1
2
[email protected]
Institute of Astrophysics, Pontificia Universidad Catolica de Chile
University of Strasbourg
131
Galaxies
Short Talks
GAL -6
The UV GRB host galaxy luminosity function
Schulze, S.B1
It is now well established that the progenitors of long gamma-ray bursts (GRBs) are collapsing massive stars.
Hence, GRB-selected galaxy studies offer a new means to map the star formation in the Universe and the fundamental routes to the formation and the build-up of high-redshift galaxies. This approach is complementary to now well-established methods leading to the zoo of galaxy populations such as LBGs, SMGs, DRGs,
LAEs, DLAs and EROs. At least for GRB host galaxies we are very sure that they point to galaxies that undergo
an intense phase of star formation. Since the beginning of GRB host studies, it was highly debated whether
GRBs are unbiased tracers of star-formation. This spawned The Optically Unbiased GRB Host Galaxy survey
(TOUGH, Hjorth et al. 2012, ApJ, 756, 187). The goal of TOUGH was to make a systematic survey of GRB
hosts regardless of burst or afterglow properties with the ESO/VLT that were complemented with the HST. In
total, the TOUGH sample comprises 69 localized GRBs, of which 80While the observed GRB host luminosity
function matches very well a star-formation-rate weighted LBG luminosity function at 2 < z < 3, we find a
clear lack of luminous galaxies at lower and higher redshifts. I will comment on the possible origins of the
lack of luminous galaxies and its implications on using GRB hosts as tracers for star formation.
B
1
[email protected]
Pontificia Universidad Católica de Chile
132
Short Talks
Galaxies
GAL -6
The Andromeda galaxy M31 in the era of precision cosmology
David Valls-GabaudB1
With the advent of precision cosmology, where predictions and measurements can be carried out to a precision level of a few percent, understanding galaxy formation and evolution to the same level of detail appears
to be essential for further tests of the paradigm. Here we review recent attempts at (1) understanding the
3-dimensional structure of the satellite system around M31, where half of the dwarfs appear to be orbiting
in a vast and thin disc; (2) anchoring M31 very accurately using three independent methods for measuring
its distance and hence the Hubble constant; and (3) establishing the variations of star-formation histories
across the galaxy through the analysis of the colour-magnitude diagrams of resolved stellar populations.
B
1
[email protected]
LERMA, Observatoire de Paris, France
133
Galaxies
Short Talks
COS -3
A data-driven approach to the emission line properties of star-forming galaxies
Sodre Jr., L.B1 ; Sirico, A. C. A.1
We present here a quantitative analysis of the correlations between the continuum and emission line equivalent widths, as well as between the equivalent widths of different lines, for a sample of more than 100,000
star-forming galaxies with high S/N spectra and with spectral synthesis performed with the Starlight software. We have done, initially, a Principal Component Analysis (PCA) of the synthesized continuum spectra
and used up to 10 components to train an artificial neural network to estimate the equivalent width of Halpha, with excellent results, demonstrating that there is indeed a strong correlation between the continuum
and the H-alpha equivalent width. We have also shown, using statistical tools such as the distance correlation and maximal information correlation, that there are important correlations between the most prominent emission lines usually detected in the optical region of galaxy spectra. The main motivation behind
this work is to produce realistic spectra for tests of data reduction pipelines of the new generation of galaxy
surveys, like the PFS/SuMIRe.
B
1
[email protected]
IAG-USP
134
Short Talks
Galaxies
GAL -7
The LMC outer disk stellar population in the light of the Dark Energy Survey
Balbinot, E.B1,2 ; Santiago, B.1,2 ; Girardi, L4 ; da Costa, L. N.2,3 ; Maia, M. A. G.2,3
The outermost regions of the Large Magellanic Clouds (LMC) have recently been covered by Dark Energy
Camera (DECam) Science Verification data, in preparation for the Dark Energy Survey (DES). Although the
DES footprint misses the bar and main star forming regions of the LMC, the available data sample a large
and continuous area of the LMC disk down to r ' 24 at distances greater than 5 degrees from its center.
This large surveyed region opened the possibility to study the outer LMC star formation history (SFH) with
unprecedented detail. In this work we employ the partial models method (Gallart et al 1999; Javiel et al 2005)
to recover the SFH and its spatial variations in the outskirts of the LMC from the observed colour-magnitude
diagrams. We take the MW foreground stars into account by modelling them with TRILEGAL (Girardi et al.
2005). With this technique we were able to recover the spatial dependency of the LMC outer components
SFH and estimate its extension as well as the inclination and depth of the LMC disk. As a byproduct of our
analysis we assembled a catalog of new LMC stellar clusters.
B
1
2
3
4
[email protected]
Instituto de Fı́sica UFRGS
Laboratório Interinstitucional de e-Astronomia
Observatório Nacional
Osservatorio Astronomico di Padova, INAF
135
Galaxies
Short Talks
GAL -7
The satellite population of Milky Way/Andromeda-sized galaxies
Avila-Reese, V.B1 ; Rodriguez-Puebla, A.1
A galaxy group mock catalog is constructed on the basis of stellar-to-(sub)halo mass relations constrained
by currently available observations (central and satellite galaxy stellar mass functions, correlation functions).
Many thousands of central galaxies of MW and M31 stellar masses are used to study several occupational distributions of their massive satellites as well as the cumulative satellite mass functions in general. We provide
also lower limits to the halo masses of MW and M31. Our analysis strongly suggests that the abundance
of subhalos agrees with that ones of satellites in all MW- and M31-sized hosts, i.e., there is not a (massive)
satellite missing problem for the LCDM cosmology. However, we confirm an internal dynamics problem for
the satellites smaller than ms ⇠ 108 M ; at difference of previous works, this conclusion is not limited to the
particular case of the MW but it refers to the overall population of MWM31-sized galaxies. Some pieces of
evidence suggest that this issue could refer only to satellite dwarfs but not to central dwarfs, in which case
astrophysical and environmental effects could be at the basis of the found differences.
B
1
[email protected]
Instituto de Astronomı́a, Universidad Nacional Autónoma de México
136
Short Talks
Galaxies
GAL -7
Star formation outside the Elliptical Galaxy NGC2865
Urrutia-Viscarra, F.B1,2 ; Arnaboldi, M.2 ; Mendes de Oliveira, C.1 ; Torres-Flores, S.3 ; de Mello, D.4 ; Carrasco, R.5
Tidal debris, rich in HI gas, formed in interacting and merging systems, may be ideal laboratories to study
star formation outside galaxies. We have searched for young stellar complexes in different systems with
optical and/or gaseous tidal tails, all of them with available archive GALEX/UV images. One of these systems
is NGC2865, which presents a ring of HI around the main galaxy. Using the Multi-Slit Imaging Spectroscopy
Technique, we detected all H↵ emitting sources in the surroundings of the galaxy NGC2865, down to a flux
limit of 10
18
[erg cm
2
s
1
A
1
]. In total, we found seven emission-line sources in a 5 x 5 arcmin (60 x 60
kpc) field over the southern tail of HI present around the galaxy NGC2865. These regions are young sources
with stellar masses in the range 4x103 M to 17x106 M , coincident with the location of the intergalactic HI
gas, where the probability to form stars is expected to be low. Given these physicals parameters, the regions
are considered young star forming regions (or clusters), born outside the galaxy. The relevance of these
observations is discussed.
B
1
2
3
4
5
[email protected]
Universidade de Sao Paulo, IAG
European Southern Observatory, Garching
Universidad de La Serena
Catholic University of America
Gemini Observatory, Southern Operations Center.
137
Galaxies
Short Talks
GAL -7
Galaxy evolution-Star formation connection: from pc to kpc scales
Melioli, C.B1 ; de Gouveia Dal Pino, E. M.1
Energization of the interstellar medium by supernova explosions covers a crucial role in a number of astrophysical situations. Supernova explosions are important for the gas evolution on small scales, because
they drive turbulence and are able to provide a self-regulation mechanism for star formation. Besides, their
blast waves may also form molecular clouds by sweeping gas into a turbulent flow. The gas heated by supernova explosions may also acquire an expansion velocity larger than the escape velocity and leave the
galaxy through a supersonic wind. The interplay between supernova explosions, stellar winds and interstellar medium is, therefore, important also for the gas evolution at large scales, playing important role on the
dynamical and chemical evolution of different galactic sistems, like dwarf, spiral and starburst galaxies and
affecting their metalicities, the surface brightness, the total gas mass evolution and the star formation rate
itself. Diffuse magnetic fields may play an important role over all these processes, because they reduce the
compressibility of a fluid and toghether with the turbulent energy may dominate over the thermal energy
in many interstellar environments, providing an important component of the verical pressure that supports
the interstellat medium, preventing the vertical expansion of superbubbles and driving galactic outflows by
cosmic ray and Alfven wave pressure. In this study we will review these mechanisms and also show 3D MHD
simulations of SN-driven turbulence in star formation regions (at small scales) and SN-driven galactic winds
(at large scales), demonstrating that stellar feedback may be able to drive new star formation processes, but
is unable to change significantly the metal abundance of the surrounding environment of the galaxies.
B
1
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências, Universidade de Sao Paulo
138
Short Talks
Galaxies
GAL -7
Herschel-ATLAS and ALMA: I. A z=1.027 Einstein Ring of Molecular Gas and Dust
Hugo MessiasB1 ; Gustavo Orellana1 ; Shane Bussmann2 ; Jae A. Calanog3 ; Helmut Dannerbauer4 ; Simon Dye5 ; Simone
Fleuren6 ; Hai Fu7 ; Edo Ibar8 ; Rob Ivison9,10 ; Andrew Inohara3 ; Neil Nagar1 ; Mattia Negrello11 ; Alain Omont12 ; Dominik
A. Riechers7,13 ; Yun-Kyeong Sheen1 ; Simon Amber14 ; Nathan Bourne5 ; Mark Birkinshaw15 ; Dave Clements16 ; Asantha
Cooray3,7 ; Stephen Eales16 ; Ricardo Demarco1 ; Loretta Dunne17 ; Roxana Lupu18 ; Steve Maddox17 ; Michal Michalowski9 ;
Dan Smith19 ; Matt Smith20 ; Elisabetta Valiante20 ; Gianfranco De Zotti11
This work focus in one lensed system selected via the Negrello et al.(2010) criterion in the Herschel-ATLAS
field. Gathering a rich multi-wavelength data-set, we have modelled the background source’s morphology
and dynamics, as well as assessed its star-formation rate (SFR) and stellar, dust, and gas (molecular and
neutral) contents. The system is comprised by a foreground edge-on disc galaxy (at zsp = 0.218) and an
almost complete Einstein ring around it, with possibly a quad-lens morphology. The background source
is at zsp = 1.027 and is magnified by a factor of ⇠4. The lens modelling is more successful in the mil-
limetre range, and supports a merger system scenario. Evidences for this come from the clumpy morphology of the reconstructed source-plane, as well as a tidal-feature observed at 1.1 µm, also predicted by the
lens-modelling of the CO(4!3) emission. The SED modelling yields a SFR of 509 M
yr
1
, in agreement
with that estimated at radio frequencies. The stellar and dust masses are, respectively, 7.6 ⇥ 1010 M and
10
1.69 ⇥ 109 M . We estimate a total molecular gas mass of MH2 = 4.86+3.21
1.31 ⇥ 10 M and a total ISM mass of
MISM = 1.1 ± 0.5 ⇥ 1011 M . The comparison between the millimetre and radio range yields no evidence for
active galactic nucleus activity. This pilot study joining Herschel and ALMA shows the strength of large-field
far-IR surveys combined with a follow-up facility such as ALMA, as a means for a systematic study of GL systems. The results already show ALMA as the ultimate tool to study GL systems, as driven by its high spectral
and spatial resolution coupled with its detectability power and integral-field spectroscopy capability.
B
[email protected]
Universidad de Concepcion, Chile
2 Harvard-Smithsonian Center for Astrophysics, Cambridge, USA
3 University of California, Irvine, USA
4 Universitä Wien, Austria
5 University of Nottingham, UK
6 Queen Mary University London, UK
7 California Institute of Technology, Pasadena, USA
8 Pontificia Universidad Catolica de Chile, Santiago, Chile
9 UK Astronomy Technology Centre, Edinburgh, UK
10 University of Edinburgh, UK
11 INAF, Padova, Italy
12 Institut d’Astrophysique de Paris, France
13 Cornell University, Ithaca, USA
14 The Open University, United Kingdom
15 Bristol University, UK
16 Imperial College London, UK
17 University of Canterbury, New Zealand
18 School of Arts & Sciences, USA
19 University of Hertfordshire, UK
20 Cardiff University, UK
1
139
140
AGN
AGN -1
IFU properties of 10 Early-type galactic nuclei
Ricci, T. V.B1 ; Steiner, J. E.1 ; Menezes, R. B.1
Active galactic nuclei (AGN) are commonly associated with the capture of matter by a supermassive black
hole (SMBH), located at the central region of galaxies. In the optical, they are characterized by intense and
broad emission lines. Quasars are the most luminous type of AGNs, both in optical and in radio. On the
other hand, Seyfert galaxies, with prominence of high ionization lines, and low ionization nuclear emission
regions (LINERs), whose low ionization emission lines tend to be more intense, belong to the low luminosity
regime of AGNs. We analyzed the central region of 10 Early-type galaxies with the GMOS-IFU spectrograph
on Gemini South telescope in order to detect and characterize low luminosity AGNs. The sample galaxies are
massive ( > 200 km s
1
) and have distances up to 30 Mpc. Using PCA Tomography and spectral synthesis
techniques in order to isolate the gas from stellar emission, we show that all galaxies of the sample possess
emission lines in their nuclei. Using standard spectral analysis, we show that all objects may be classified
as LINERs. In six galaxies, we detected a broad H↵ component, which confirms the presence of an AGN in
these objects.
B
1
[email protected]
IAG - Universidade de São Paulo
141
AGN
Short Talks
AGN -1
Co-evolution of Supermassive Black Holes and Galaxies in the near Universe
Thaisa Storchi-BergmannB1
Although the bulk of the supermassive black hole (SMBH) growth has occurred at redshifts higher than 2,
the feeding processes cannot be resolved at the corresponding distances. It is in the near Universe that these
processes – which take place within the inner few hundred parsecs of active galaxies – can be probed down
to ⇠ 10 pc spatial resolution. I will discuss integral field spectroscopic observations of the inner kiloparsec
of nearby active galaxies which reveal the presence of gas reservoirs and inflows along nuclear spirals and
filaments. The derived mass inflow rates are ⇠ 3 orders of magnitude larger than the mass accretion rate to
the SMBH and can lead, during an activity cycle, to the accumulation of enough gas in the inner few hundred
pc’s to trigger the formation of new stars. This result suggests that co-evolution of SMBH and galaxies is still
occurring in the near Universe. The observations also reveal the presence of outflows at similar mass flow
rates to that of the inflows, although the inflows are best seen around LINER nuclei and the outflows around
Seyfert nuclei, what may imply evolution between these two types of activity.
B
1
[email protected]
Instituto de Fı́sica, Universidade Federal do Rio Grande do Sul
142
Short Talks
AGN
AGN -1
Gap Formation in Circumbinary AGN Disks
Escala, A.B1 ; Del Valle, L.1
We numerically study the formation of gaps in circumbinary disks of comparable mass massive black hole
binaries (q ⇠ 1). We vary the disk properties (mass, termodynamics, etc.) and found that most massive and
thicker disks are able to prevent the gap formation in them. We contrast our results against analytical models
based on the non-axisymetric perturbation enhanced in the disk, which succesfully predicts the disks that
opens a gap. We discuss the implications for the occurence of opened and failed gaps in the final separations
and posible merging of binary AGNs.
B
1
[email protected]
Universidad de Chile
143
AGN
Short Talks
AGN -1
Coronal Emission in the Active Galactic Nuclei and its relationship to outflows
Rodriguez-Ardila, A.B1 ; Mazzalay, Z.2 ; Riffel, R.3
SOAR/Goodman spectroscopy is employed to detect the coronal lines [Fe VII] 3759, 5159, 6087 Å, [Ne V] 3423 Å
and [Fe X] 6083 Å, in a sample of 12 active galactic nuclei (AGN). The three [Fe VII] lines are found to be suitable to determine the temperature and density of the high-ionization gas, allowing us to determine, for the
first time, the physical conditions of the coronal line region in these objects. The spectra are also employed
to fully characterize the profiles of the most conspicuous coronal lines and the low ionization gas (asymmetries, shifts from the centroid position, line width and kurtosis) and to relate these properties to the presence
of nuclear ouflows. The combined results allow us to associate the detection of broad highly assymmetric
forbidden line profiles to hot (Te > 3 ⇥ 104 K) and high-density (ne > 104 cm
3
) gas, suggesting that it orig-
inates very likely from nuclear outflows. Most of the coronal emission is highly compact. However, in a few
objects, coronal emission up to 1000 from the galaxy nucleus is detected, mostly in radio-sources, suggesting
that shocks between the radio-jet and the ISM medium can also be responsible for the emission of highly
ionized species. All above results allow us to confirm the role that coronal lines have to trace outflows either
at the inner regions or at kiloparsec scales of AGNs.
B
1
2
3
[email protected]
Laboratorio Nacional de Astrofı́sica / MCTI
Max-Planck-Institut für Extraterrestrische Physik
Universidade Federal do Rio Grande do Sul
144
Short Talks
AGN
AGN -2
Gas dynamics in the Galactic Centre: clump accretion and outflows
Cuadra, J.B1
We present numerical models of the gas dynamics in the central parsec of the Galaxy, from its origin as stellar
winds, until its capture by Sgr A*, the central massive black hole. We show that the gas forms a two-phase
medium, with cold clumps embedded in a hot tenuous gas. We find the accretion rate to be variable, due to
the effect of the stellar orbits and the stochastic accretion of clumps. We suggest that the recently discovered
infalling cloud, G2, could be one of the predicted clumps. We also study the possibility of detecting the effect
of a recent outflow from Sgr A*.
B
1
[email protected]
Instituto de Astrofı́sica, Pontificia Universidad Católica de Chile
145
AGN
Short Talks
AGN -2
Parsec-scale Activity in BL Lacertae: Signature of Relativistic Jet Precession
Caproni, A.B1 ; Abraham, Z.2 ; Monteiro, H.3
BL Lacertae is the prototype of the BL Lac class of active galactic nuclei. High-resolution interferometric
images at radio wavelengths show the presence of a compact core and a diffuse halo-like source at arcsecond scales, while at an intermediate resolution (<
⇠ 10 mas), BL Lacertae shows a core-jet structure. At
parsec scales, BL Lacertae exhibits intensive activity, such as intense core variability and multiple ejections
of superluminal jet components, with components following different trajectories on the plane of the sky.
In this work we analyze temporal changes of the observed right ascension and declination core-component
offsetsin BL Lacertae in terms of our relativistic jet-precession model. The seven free parameters of our
precession model were optimized via a heuristic cross-entropy method, comparing the projected precession
helix with the positions of the jet components on the plane of the sky and imposing constraints on their
maximum and minimum superluminal velocities. Our optimized best model is compatible with a jet having
a bulk Lorentz factor of 5.4, which is precessing with a period of about 12.1 yr in the observer’s reference
frame and changing its orientation in relation to the line of sight between 4o and 5o , approximately.
B
1
2
3
[email protected]
Núcleo de Astrofı́sica Teórica - Universidade Cruzeiro do Sul
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas - Universidade de São Paulo
Instituto de Ciências Exatas - Universidade Federal de Itajubá
146
Short Talks
AGN
AGN -2
The incidence of short time scale variability on different types of Blazars
Andruchow, I.B1,2 ; Cellone, S. A.1,2 ; Romero, G. E.1,3
Active Galactic Nuclei (AGNs) have an extreme behavior at almost all wavelengths. In particular, the kind of
AGNs know as blazars are one of the most extreme. With their jets pointing near to our direction, those object
show a variety of distinctive features from radio to very high energies. We present the results of an extended
campaign to study the behavior of the optical emission of blazars. This work is centered on variability at
short scales of both the total flux (at different optical wavebands) and the linear optical polarization. We
took special care in data treatment, e.g. considering the influence of the host galaxies, the good choice of the
field stars used for differential photometry, the statistical test used to study the variability, etc. Over the last
years, we specially followed blazars that were detected at very high energies (TeV). We found differences in
the incidence of variability at short time-scales between blazars that have the peak of their synchrotron flux
low frequencies from those that have it at high energies.
B
1
2
3
[email protected]
Facultad de Ciencias Astronómicas y Geofı́sicas, UNLP
Instituto de Astrofı́sica de La Plata, CONICET
Instituto Argentino de Radioastronomı́a, CONICET.
147
AGN
Short Talks
AGN -2
The Multiwavelength Study of OH Megamaser Galaxy IRAS16399-0937
Dinalva A. SalesB1 ; A. Robinson; D. J. Axon; J. Gallimore; P. Kharb; R. L. Curran; C. O’Dea; S. Baum; R. Mittal
In this work we present a spectacular morphology of OH Megamaser galaxy (OHMG) IRAS16399-0937 taken
from our HST snapshot imagery program. We also conduce a detailed multi-wavelength analysis of IRAS163990937 using HST/NICMOS, 2MASS, Spitzer (IRAC, IRS, and MIPS) as well as Herschel/SPIRE data archive. The
HST H↵+[NII] and F814W image of IRAS16399-0937 reveal a dual point like source seeming in the middle to
final stage of interaction with a projected separation of ⇠ 6 (3.4 kpc) with a dust lane crossing through LINER
(North) and Starburst (South) nuclei and a bright tail arc of dust and gas connecting a both nuclei. The North
and South nuclei, as well as interstellar medium (ISM) of this merger system show strong feature of the polycyclic aromatic hydrocarbons (PAH) molecules, which is indicator for recent star formation activity, in the
mid-IR (MIR) Spitzer spectra. However, the MIR spectrum of the whole IRAS16399-0937 system presents
only ionic emission lines with low ionization potential (IP < 50 eV) and no evidence of those that is a clear
indicator of powerful AGN activity. The same scenario was found to that nucleus (North) classified as active
galactic nuclei (AGN) in the optical wavelength. In spite of the lack of a direct evidence of AGN activity to the
North nucleus the decomposition of the optical - FIR spectral energy distribution (SED) using our own tool,
CLUMPY DREAM,
find a moderately powerful AGN (Lbol ⇠ 1.24 ⇥ 1044 ergs/s) quite embedded in a clumpy
torus environment. Overall, our observations emphasize a presence of an AGN and Starburst nuclei in major
IRAS16399-0937 merger.
B
1
2
3
[email protected]
Department of Physics, Rochester Institute of Technology, 84 Lomb Memorial Drive, Rochester, NY 14623, USA
Department of Physics Bucknell University Lewisburg, PA 17837, USA
Indian Institute of Astrophysics, II Block, Koramangala, Bangalore - 5600034, India
148
Short Talks
AGN
AGN -3
AGN torus properties with WISE
B1,2
Nikutta, R.
; Nenkova, M.3 ; Hunt-Walker, N.4 ; Ivezic, Z.4 ; Elitzur, M.2
The WISE satellite mission has collected an unprecedented infrared dataset. Its four photometric filter bandpasses at 3.4, 4.6, 12 and 22 micron enable studies of dust emission from various astronomical sources, including quasars and Active Galactic Nuclei (AGN). With its sensitivity up to 1000 times better than previous
missions (e.g. IRAS) and a spatial resolution between 6 and 12 arcsec, WISE measured brightness and colors
on hundreds of millions of point sources, and among them many tens of thousands of AGN.
Using a large cross-matched sample of previously classified SDSS objects, we define reliable selection
criteria for type-1 AGNs with dust torus emission. Aided by our large database of CLUMPY torus models
(Nenkova et al. 2008a,b), we identify the ranges of model parameter values supported by WISE observations,
and derive likely properties of AGN tori in general. Unlike previous studies, this AGN torus characterization
has been performed with high statistical significance thanks to the unprecedentedly large sample size.
For the very first time we are now able to predict the number of observable type-2 AGN from an observed
sample of unobscured type-1 objects. We also derive color selection criteria for type-2 sources using best-fit
models for confirmed type-1 sources but with complementary viewing angles (i.e. preferentially edge-on
lines of sight). We find that type-2 objects are type-2 precisely because they are intrinsically more likely to
be observed along optically obscured lines of sight: type-1 and type-2 AGN have significantly different dust
covering factors and line-of-sight photon escape probabilities. Finally, using recent studies of BL Lac objects,
we show that in certain configurations CLUMPY torus models are compatible with the relatively blue WISE
colors seen in these sources.
B
1
2
3
4
[email protected]
Departamento de Ciencias Fisicas, Universidad Andres Bello, Santiago/Chile
Department of Physics and Astronomy, University of Kentucky, Lexington/USA
School of English and Liberal Studies, Seneca College, Toronto/Canada
Astronomy Department, University of Washington, Seattle/USA
149
AGN
Short Talks
AGN -3
HST and Spitzer point source and dust lane detection in powerful narrow-line radio
galaxies
Edgar A. RamirezB1 ; C. N. Tadhunter2 ; D. Dicken3 ; M. Rose2 ; D. Axon4,5 ; W. Sparks6
We present the analysis of infrared HST and Spitzer data for a sample of 13 FRII powerful radio galaxies at
0.03 < z < 0.11 that are optically classified as narrow-line radio galaxies (NLRG). Under the context of the
unified schemes of Active Galactic Nuclei (AGN), the direct view of the AGN in NLRG is impeded by a parsecscale toroidal structure when this is viewed edge-on. Our high resolution infrared observations provide new
information about the optical extinction, orientation, and direct AGN detection of the inner kpc-scale region
of the AGN.
We have found that the point-like nucleus detection rate increases from 25% detected at 1.025 µm to 80%
and 100 detection rate at 2.05 and 8 µm, respectively. This detection towards longer infrared wavelengths
supports the idea that a large proportion of NLRG host an obscured AGN in their centre. Furthermore, at
1.025 µm, we detect a kpc-scale dust lane in 70% of our sample, of which 55% are perpendicular to their
inner kpc radio jet axis. Assuming that the torus is perpendicular to the radio jet, this suggests a continuity
from the parsec-scale torus to the kpc-scale dust lane.
The optical extinction produced by the obscuring structures have been estimated from X-rays, near-IR
and mid-IR data using five different methods. All the extinction estimates are consistent (AV = 3
170 mag),
with the exception of that estimated using the silicate absorption line, which is lower (AV = 0
25 mag).
This discrepancy challenges the simplified idea of an homogeneous dust torus extinguishing the AGN light
as a foreground screen. The disagreement can be explained by thermal mid-IR emission from an extended
narrow-line region, by non-thermal emission from the base of the radio jets, or by a clumpy torus model
diluting the silicate absorption line.
B
1
2
3
4
5
6
[email protected]
IAG- U. Sao Paulo
Department of Physics and Astronomy, University of Sheffield
Institut d’Astrophysique Spatiale, Université Paris Sud
Physics Department, Rochester Institute of Technology
School of Mathematical and Physical Sciences, University of Sussex
SpaceTelescope Science Institute, Baltimore
150
Short Talks
AGN
AGN -3
Collimation and scattering of the AGN emission in the Sombrero galaxy
Menezes, R. B.B1 ; Steiner, J. E.1 ; Ricci, T. V.1
M104, the Sombrero galaxy, is a highly inclined (nearly edge-on) SA(s)a galaxy at a distance of about 9.2
Mpc. Based on its optical emission line spectrum, the nucleus of this object has been classified as a LINER
(Low Ionization Nuclear Emission-line Region). We present an analysis of a data cube of the central region
of M104, obtained with the GMOS-IFU of the Gemini-South telescope, and report the discovery of collimation and scattering of the AGN emission in the circum-nuclear region of this galaxy. Analysis with PCA
Tomography and spectral synthesis revealed the existence of collimation and scattering of the AGN featureless continuum and also of a broad component of the H↵ emission line. The collimation and scattering of
this broad H↵ component was also revealed by fitting the [N II]
6548, 6583 and H↵ emission lines as a sum
of Gaussian functions. The spectral synthesis, together with a V-I image obtained with the HST, showed the
existence of circum-nuclear dust, which may cause the light scattering. We also identify a dusty feature that
may be interpreted as a torus/disk structure. The existence of two opposite regions with featureless continuum along a direction perpendicular to the torus/disk suggests that this structure is approximately edge-on
and collimates the AGN emission. The edge-on torus/disk also hides the BLR. The proposed scenario is
compatible with the Unified Model and explains why only a weak broad component of the H↵ emission line
is visible and also why many previous studies detected no broad H↵.
B
1
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, Universidade de São Paulo
151
AGN
Short Talks
AGN -3
The Role of AGN Feedback in the Evolution of Seyfert Galaxies
Mueller-Sanchez, F.B1 ; Malkan, M.1 ; Hicks, E.2 ; Davies, R.3
Adaptive optics integral-field observations of Seyfert Galaxies have recently revealed clear evidence of AGNdriven outflows of ionized gas. By resolving the inner 10-20 parsecs, we are successfully modeling the geometry and kinematics of the outflows in 3D. The model parameters are used to estimate mechanical feedback
from the AGN and test unification models. The mass outflow rates are 2–3 orders of magnitude greater than
the accretion rates, but they are comparable to the estimated inflow rates to the central 10-25 pc, suggesting that the outflows may remove a considerable amount of the infalling gas before it reaches the accretion
disk. The outflows seem to form two distinct groups which differ by outflow power variations with radio flux.
While powerful outflows (with kinetic powers > 1.0% Lbol) are observed in objects with extended radio jets,
in the other AGN -in which the outflow power is less than 0.1% Lbol- the radio jet is weak and compact.
B
1
2
3
[email protected]
University of California Los Angeles
University of Washington
MPE, Germany
152
Cosmology
COS -1
The Local Group in a explicit cosmological context
Jaime E. Forero-RomeroB1 ; Yehuda Hoffman2 ; Sebastian Bustamante3 ; Stefan Gottloeber4 ; Gustavo Yepes5
In this talk we present recent results on the effort to simulate the Local Group (LG, composed by the Milky
Way and M31) in a explicit cosmological context. The main results are obtained through cosmological Nbody simulations which use constrained initial conditions that aim at reproducing the observed large scale
environment. We show that in the constrained simulations there is a bias in the formation properties of the
simulated LG and also that the observed radial motion of Andromeda towards us is not common in the context provided by LCDM. In the effort to better understand these results, we finish by discussing preliminary
results on the effect of the cosmic web on the formation of LG-like systems.
B
1
2
3
4
5
[email protected]
Departamento de Fisica, Universidad de los Andes, Colombia
Racah Institute of Physics, Hebrew University of Jerusalem
Instituto de Fisica - FCEN, Universidad de Antioquia
Leibniz Institut fuer Astrophysik - Potsdam
Grupo de Astrofisica, Departamento de Fisica Teorica, Universidad Autonoma de Madrid
153
Cosmology
Short Talks
COS -1
Cosmology from the Angular Correlation Function and Galaxy Clusters
Marcos LimaB1 ; Hugo Camacho; Michel Aguena; DES-Brazil consortium
The large-scale clustering properties of galaxies allows us to investigate models which attempt to explain
the recent acceleration of the Universe background expansion. These properties include the correlations of
galaxies and the abundance of galaxy clusters. I will present some of the relevant aspects when using these
probes to constrain cosmological models. If time allows I will also present some of our recent results on real
data from the Sloan Digital Sky Survey DR8 and on mock catalogs of the Dark Energy Survey.
B
1
[email protected]
Instituto de Fı́sica, Universidade de São Paulo
154
Short Talks
Cosmology
COS -1
Halo-based reconstruction of the cosmic mass density field
Muñoz-Cuartas, J. C.B1 ; Müller, V.2 ; Forero-Romero, J. E.3
We present the implementation of a halo-based method for the reconstruction of the cosmic mass density
field. The method employs the mass density distribution of dark matter haloes and its environments computed from cosmological N-body simulations and convolves it with a halo catalogue to reconstruct the dark
matter density field determined by the distribution of haloes. We applied the method to the group catalogue
of Yang et al. built from the Sloan Digital Sky Survey (SDSS) Data Release 7. As a result we obtain reconstructions of the cosmic mass density field that are independent of any explicit assumption of bias. We describe
in detail the implementation of the method, present a detailed characterization of the reconstructed density
field (mean mass density distribution, correlation function and counts in cells) and the results of the classification of large-scale environments (filaments, voids, peaks and sheets) in our reconstruction. Applications
of the method include morphological studies of the galaxy population on large scales and the realization of
constrained simulations.
B
1
2
3
[email protected]
Instituto de Fisica, Universidad de Antioquia, Medellin-Colombia
Leibniz-Institut für Astrophysik Potsdam
Departamento de Fisica, Universidad de los Andes, Bogota-Colombia
155
Cosmology
Short Talks
COS -1
Globular clusters as tracers of the hierarchical formation of the Milky Way
Carballo-Bello, J. A.B1,2,3 ; Martı́nez-Delgado, D.4 ; Sollima, A.5 ; Muñoz, R.1
Globular clusters have played an important role in the study of the processes that led to the formation of our
Galaxy. Moreover, the dual Galactic globular cluster system is considered a manifestation of its hierarchical formation in the context of the Lambda-CDM scenario. Wide-field imaging - as the one obtained in our
work - and follow-up spectroscopy are crucial tools to unveil the remnants of their progenitor dwarf galaxies,
already assimilated by the Milky Way. In this talk, I will review some of the clues pointing to the external origin of an important fraction of the Galactic globular clusters and the importance of these interesting stellar
systems in the searching for known and unknown halo substructures and tidal streams.
B
1
2
3
4
5
[email protected]
Departamento de Astronomı́a, Universidad de Chile
Instituto de Astrofı́sica de Canarias
Departamento de Astrofı́sica, Universidad de La Laguna
Max Planck Institut für Astronomie
Osservatorio Astronomico di Bologna
156
Short Talks
Cosmology
COS -1
Huge-LQG- the largest structure in the universe
Roger G. Clowes ; Srinivasan Raghunathan2 ; Kathryn A. Harris3 ; Luis E. CampusanoB2 ; Ilona K. Sochting4 ; Matthew
1
J. Graham5
A large quasar group (LQG) of particularly large size and high membership has been identified in the DR7QSO
catalogue of the Sloan Digital Sky Survey. It has characteristic size (volume1/3 ) ⇠ 500 Mpc (proper size,
present epoch), longest dimension ⇠ 1240 Mpc, membership of 73 quasars and mean redshift z=1.27. In
terms of both size and membership, it is the most extreme LQG found in the DR7QSO catalog for the redshift range 1.0 < z < 1.8 of our current investigation. Its location on the sky is ⇠ 8.8 degrees north (⇠ 615
Mpc projected) of the Clowes & Campusano LQG at the same redshift, z=1.28, which is itself one of the more
extreme examples. This new, Huge-LQG appears to be the largest structure currently known in the early Universe. Its size suggests incompatibility with the Yadav et al.(2010) scale of homogeneity for the concordance
cosmology, and thus challenges the assumption of the cosmological principle.
B
1
2
3
4
5
[email protected]
Jeremiah Horrocks Institute, University of Central Lancashire, UK
Departamento de Astronomı́a, Universidad de Chile, Santiago, Chile
Department of Physics, Virginia Tech, Blacksburg, VA
Astrophysics, Denys wilkinson Building, Keble Road, University of Oxford, UK
California Institute of Technology, Pasadena, CA
157
Cosmology
Short Talks
COS -2
The SOAR Gravitational Arc Survey
B1
Makler, M.
2,3
; Furlanetto, C. ; Santiago, B. X.2,3 ; Caminha, G. B.1 ; Cypriano, E.4 ; Cibirka, N.4 ; Pereira, M. E. S.1 ;
Bom, C. R. D.1 ; Lima, M. P.1,5 ; Brandt, C. H.1 ; Neto, A. F.3 ; Estrada, J.6 ; Lin, H.6 ; Hao, J.6 ; McKay, T. M.7 ; da Costa, L. A. N.3,8 ;
Maia, M. A. G.3,8
We present the first results of the SOAR Gravitational Arc Survey (SOGRAS). The survey imaged 47 clusters in
two redshift intervals centered at z = 0.27 and z = 0.55, targeting the richest clusters in each interval. Images
were obtained in the g 0 , r0 and i0 bands with a median seeing of 0.83, 0.76 and 0.71 arcsec, respectively, in these
filters. Most of the survey clusters are located within the Sloan Digital Sky Survey (SDSS) Stripe-82 region and
all of them are in the SDSS footprint. We present the first results of the survey, including the 6 best strong
lensing systems, photometric and morphometric catalogs of the galaxy sample, and cross matches of the
clusters and galaxies with complementary samples (spectroscopic redshifts, photometry in several bands,
X-ray and Sunyaev Zel’dovich clusters, etc.), exploiting the synergy with other surveys in Stripe-82. We apply
several methods to characterize the gravitational arc candidates, including the Mediatrix method (Bom et al.
2012) and ArcFitting (Furlanetto et al. 2012), and for the subtraction of galaxy cluster light. Finally, we apply
strong lensing inversion techniques to the best systems, providing constraints on their mass distribution.
The analyses of a spectral follow-up with Gemini and the derived dynamical masses are presented in a poster
submitted to this same meeting (Cibirka et al.).
Deeper follow-up images with Gemini strengthen the case for the strong lensing nature of the candidates
found in this survey.
B
1
2
3
4
5
6
7
8
[email protected]
Centro Brasileiro de Pesquisas Fı́sicas
Departamento de Astronomia, Universidade Federal do Rio Grande do Sul
Laboratório Interinstitucional de e-Astronomia
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, Universidade de São Paulo
Instituto Nacional de Pesquisas Espaciais
Center for Particle Astrophysics, Fermi National Accelerator Laboratory
Department of Physics, University of Michigan
Observatório Nacional
158
Short Talks
Cosmology
COS -2
A Systematic Study of the NFW and SIS Elliptical Lensing Models in the Strong Regime
Dúmet-Montoya, H. S.B1 ; Caminha, G. B.1 ; Makler, M.1
The increasing number of gravitational arc systems expected to be detected in the next generation widefield surveys requires the fast numerical evaluation of lensing quantities to obtain the matter distribution
of lenses and to make predictions for arc statistics in several cosmologies. It is therefore useful to employ
approximate (or semi-analytical) methods to speed up the numerical computations. In this presentation we
discuss two such classes of methods.The first one is to use pseudo-elliptical models (with lensing potential
constant over ellipses) instead of elliptical ones (with surface mass density constant over ellipses), which are
more physically motivated, but more computationally complex. The second one is to use the Perturbative
Approach (PA) that provides approximate solutions for the lens equation near the tangential critical curve,
leading to analytic solutions for arcs. We present our recent progress on inverse modelling and arcs statistics
for models based on the Singular Isothermal Sphere (SIS) and Navarro–Frenk–White (NFW) density profiles,
widely used to represent lenses from galaxy to cluster of galaxies mass scales. We derive analytic solutions
for the Singular Isothermal Ellipsoid (SIE) and Elliptic Potential (SIEP), which are valid even in the presence
of constant convergence and shear fields. These solutions include i) the lens equations for elliptical finite
sources, ii) iso-convergence contours and constant distortion curves (including critical curves) and iii) the
deformation cross section. We also investigate the mapping between the Elliptic and Pseudo-Elliptic NFW
models (ENFW and PNFW) deriving constraints on the ellipticity as a function of convergence such that the
PNFW can replace the ENFW to represent the mass distribution and deformation cross section. In the limit of
small characteristic convergences we obtain analytic solutions for i) iso-convergence contours and constant
distortion curves and ii) the deformation cross section. We implemented the PA for pseudo-elliptical models deriving analytic solutions for i) the lens equations for finite sources, ii) for constant distortion curves
and iii) an approximate formula (up to second order in the ellipticity parameter) for the deformation cross
section. We show that the solution of the PA for the SIEP model is exact. For the PNFW we determine a
domain of validity on the space of model parameters such that the PA can replace the exact solutions for
constant distortion curves and deformation cross section. The solutions and mapping relations presented
here, within their determined domain of validity, can be used to speed up numerical codes and applied to
arc statistics and other lensing observables.
B
[email protected]
Instituto de Cosmologia, Relatividade e Astrofı́sica — ICRA, Centro Brasileiro de Pesquisas Fı́sicas, Rua Dr. Xavier Sigaud 150, CEP
22290-180, Rio de Janeiro, RJ, Brazil
1
159
Cosmology
Short Talks
COS -2
The CFHT/MegaCam Stripe-82 Survey
B1
Moraes, B.
2
; Kneib, J.-P. ; Leauthaud, A.3 ; Makler, M.1 ; Van Waerbeke, L.4 ; Bundy, K.3 ; Erben, T.5 ; Heymans, C.6 ;
Hildebrandt, H.4,5 ; Miller, L.7 ; Shan, HY.8,9 ; Woods, D.4 ; Charbonnier, A.1 ; Pereira, M. E.1
The CFTH/MegaCam Stripe-82 Survey (CS82) is a joint Canada-France-Brazil project covering ⇠ 170 sq. deg.
in the SDSS Stripe-82 area down to magnitude 24.1 in the optical i-band with a mean 0.6” seeing (PIs: J.-P.
Kneib, A. Leauthaud, M. Makler, L. Van Waerbeke). Its main focus is the study of weak and strong gravitational lensing, with additional applications in other fields such as galaxy evolution and galaxy cluster science. Furthermore, the multitude of existing and future projects in Stripe-82, covering from the radio to the
UV and including a large set of spectroscopic data, offers the possibility of exploring applications in many
fields of astronomy, thereby enhancing the scientific value of the survey. In this Short Talk, we will give an
overview of the main published and ongoing CS82 scientific projects. They include the measurement of
the largest contiguous lensing convergence map to date and its peak statistics, providing direct information
on the large scale dark matter distribution; the first CMB-lensing ⇥ shear cross-correlation measurement,
probing the dark matter distribution at redshifts of order 1; galaxy-galaxy lensing measurements around
SDSS-III/BOSS galaxies, constraining halo occupation distribution (HOD) models and obtaining complementary mass measurements in combination with BOSS spectroscopic data; the discovery of several new
gravitational arc systems and more.
B
1
2
3
4
5
6
7
8
9
[email protected]
ICRA, Centro Brasileiro de Pesquisas Fı́sicas
Laboratoire d’Astrophysique de Marseille, Aix Marseille Université
Institute for the Physics and Mathematics of the Universe, University of Tokyo
Department of Physics and Astronomy, University of British Columbia
Argelander Institute for Astronomy, University of Bonn
Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Royal Observatory
Department of Physics, Oxford University
Laboratoire d’astrophysique, Ecole Polytechnique Fédérale de Lausanne
Department of Physics and Tsinghua Center for Astrophysics, Tsinghua University
160
Short Talks
Cosmology
COS -2
High Mass X-ray Binaries at the Dawn of the Universe
I. F. MirabelB1
Based on the observations of accreting stellar black holes in the local universe, I propose that a large fraction of the first generations of massive stars in primordial galaxies ended as black holes and neutron stars in
High Mass X-ray Binaries. Besides the ultraviolet radiation from their massive stellar progenitors, feedback
from HMXBs was an additional, important source of heating and reionization of the IGM. X-rays and relativistic jets from the large populations of HMXBs, determined the early thermal history of the universe and
maintained it ionized over large volumes of space. This has a direct impact on the properties of the faintest
galaxies at high redshifts, the smallest dwarf galaxies in the local universe, and on the existing and future
surveys at radio wavelengths of atomic hydrogen in the early universe.
B
1
[email protected]
IAFE-CONICET-Argentina
161
Cosmology
Short Talks
COS -3
Multi-fractal and lacunarity spectrum analysis of the galaxy distribution in the SDSS
9th data release
Chacón-Cardona, C. A.1,2 ; Casas-Miranda, R. A.B2
The cosmological principle states that the cosmos is homogeneous and isotropic, such that the observed
inhomogeneities are only perceived locally and should vanish on sufficiently large scales. In modern cosmology the cosmological principle is one of the fundamental hypotheses from which the observations and
theoretical developments are contrasted and interpreted. Thus, it is important to investigate if the cosmological principle is supported by the observations of galaxies in the most recent catalogues and, in the affirmative case, what is the distance scale at which the transition to homogeneity is observed. Some researchers
report that astrophysical objects are grouped in highly structured hierarchical patterns that exhibit properties of self-similarity and a fractal dimension smaller than the physical space dimension (i.e., no transition
to homogeneity), while other authors claim to have found the scale of transition to homogeneity.
We develop a statistical analysis of the large-scale clustering of matter in the universe from the fractal
point of view using galaxies from the Ninth Sloan Digital Sky Survey (SDSS) Data Release (DR9). From the
total set of galaxies, a galaxy sample with redshifts in the range 0 < z < 0.25 is created. The sample covers the
largest completely connected area of the celestial sphere within the catalogue, with limits in right ascension
of 120 < ↵ < 240 and declination 0 <
< 60 , which is a region that includes the largest galactic samples
that have been studied from the fractal viewpoint to date. From this initial sample which contains 296,465
galaxies we create four volume-limited samples in order to avoid radial incompleteness that would create a
spurious detection of clustering up to the largest scales analyzed.
We use the sliding-window technique to determine the multi-fractal dimension, the lacunarity spectrum
and its dependence on radial distance from the centers for the four volume limited samples used. Using
these statistical tools, we find that the clustering of galaxies shows a fractal behavior, that is function of the
radial distance, for all calculated quantities. A transition to homogeneity is not observed in the complete
multi-fractal dimension set; instead, the galaxies exhibit a persistent multi-fractal behavior with a dimensional spectrum that does not reach the physical space dimension for all values of the structure parameter
analyzed, at least for radial distances up to 140 Mpc/h from each available center within the four volumelimited samples. Our results are discussed in the context of the formation of large-scale structure in the
Universe.
B
1
2
[email protected]
Facultad Tecnológica, Universidad Distrital ”Francisco José de Caldas”
Universidad Nacional de Colombia
162
Short Talks
Cosmology
COS -3
Contrast density and mass function for spherical collapse of Lemaitre-Tolman-Bondi
metric since fractal point of view.
Chacón-Cardona, C. A.B1,2 ; Casas-Miranda, R. A.1
In the nearby universe large inhomogeneities are observed, the galaxies are grouped in comparatively small
sections of the space while larges voids are frequently found between the galaxy clusters. According to the
standard cosmological principle this behavior must give pass to a statistical homogeneity on a scale that
some research groups have located around 100 Mpc/h. On the other hand, recent works on the clustering
of astrophysical objects put into question the homogeneity transition universally accepted. Whether or not
there is a definite transition to homogeneity, local inhomogeneities should lead us to consider whether physical models based on the cosmological principle are really consistent with observations. Since the dawn of
general relativity several researchers have been working on non-homogeneous models of the universe, showing us alternative cosmological research ways both in data interpretation as in theoretical developments.
In this presentation we show a theoretical development for the mass density contrast required for the
spherical collapse of a dark matter over-density perturbation that evolves in a non-homogeneous universe.
In our development we use the fractal cosmology with the Lemaitre-Tolman-Bondi (LTB) metric developed
by Ribeiro in the 1990’s. First we demonstrate the correspondence between the respective quantities in the
standard cosmology in a homogeneous Friedmann-Robertson-Walker universe and our development based
on the fractal metric when the dimension of the mass enclosed in a sphere of co-moving radius r obtained
from the fractal metric takes the same value of the physical space dimension D = 3, i.e., homogeneity condition.
We find an expression for the halo mass function within the Press-Schechter formalism using the theory
of brownian random paths, also known as excursion set theory. Finally, we compare our results with the
galaxy clustering information from the Millennium Simulation and from the Sloan Digital Sky Server (SDSS)
galaxy catalogue in its ninth data release. Our theoretical model and its predictions are discussed in the context of the large-scale structure formation in the Universe from the viewpoint of the conditional cosmological
principle proposed by Mandelbrot.
B
1
2
[email protected]
Universidad Nacional de Colombia, Departamento de Fı́sica
Universidad Distrital Francisco José de Caldas, Facultad Tecnológica
163
Cosmology
Short Talks
COS -3
Gaussian analyses on PLANCK CMB maps
Bernui, ArmandoB1
Extremely precise cosmic background radiation (CMB) data from Planck satellite confirmed the cosmological model ⇤CDM and established tight constraints for several features of the primary and secondary CMB
temperature fluctuations. Possible non-Gaussian (NG) contributions to the CMB field could be originated
during (or soon after) primordial cosmic inflation, where the types, scale dependences, and intensities expected depend on the inflationary models. For this, the robust detection –or not– of primordial NG in the
CMB signify a unique probe to the early universe, allowing to distinguish between competing models. Recent analyses from Planck CMB data strongly limit the level of NG and show consistency with the Gaussian
hypothesis although they do not exclude the presence of weak Gaussian deviations. A problem inherent
with the confidence of a positive detection is the possibility that any non-primordial contamination could
be mixed with primary contributions leading to qualitative and/or quantitative imprecise detections.
A variety of methods are being used to search for different NG signals in CMB data because one does not
expect that a single statistical tool can be able to identify all possible forms of Gaussian deviations. Using two
directional large-angle NG indicators based on skewness and kurtosis statistical momenta of patches of the
CMB sphere, we analyze the three nearly full sky foreground-cleaned Planck maps: SMICA, NILC, and SEVEM.
Our results show that these foreground-cleaned Planck maps exhibit different levels of NG at large angles,
depending on the cut-sky mask used (all of them released by the Planck collaboration). The separation
component minimum mask, termed M82, and the U73 mask appear to be equally efficient to Gaussianize
all these CMB Planck maps.
B
1
[email protected]
Observatório Nacional, MCTI
164
High Energy Astrophysics
HEAP-1
Acceleration of Cosmic Rays in the FERMI and CTA Era
de Gouveia Dal Pino, E. M.B1 ; Kowal, G.2 ; Lazarian, A.3
The gamma ray emission detected from cosmic sources is currently challenging the researchers. Its origin is
in most cases associated to cosmic ray production. Very fast particles may be accelerated by a variety of processes. In particular, acceleration by magnetic reconnection has lately attracted the attention of researchers
not only for its potential importance in the solar system context, but also beyond it, in astrophysical environments like galactic black holes, pulsars, AGNs and GRBs, and even in the diffusive ISM and IGM, especially
in magnetically dominated regions. In this talk, we review this process and present three-dimensional MHD
simulations of astrophysical sites with the injection of thousands of test particles and show from the evolution of their energy spectrum that they are efficiently accelerated by reconnection through a first-order
Fermi process within large scale magnetic current sheets (especially when local turbulence is present making reconnection fast and the acceleration region thick). The resulting acceleration will be also confronted
with shock acceleration in distinct cosmic ray accelerators.
B
1
2
3
[email protected]
Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo
EACH, Universidade de Sao Paulo
Astronomy Department, University of Wisconsin at Madision
165
High Energy Astrophysics
Short Talks
HEAP-1
The Gravitational Drag Force on an Extended Object Moving in a Gas
Bernal, C. G.B1 ; Sánchez-Salcedo, F. J.1
A gravitational perturber moving through a gaseous background creates a density wake in the medium. At
large enough impact parameters, the perturber induce a small perturbation in the far-field ambient medium
and the density structure of the wake can be derived in linear perturbation theory. Using this approach, Ostriker (1999) derived the density wake behind a gravitational body of mass M moving at velocity V0 on a
straight-line trajectory through a homogenous medium with unperturbed density rho0 and sound speed c0 ,
when the perturber is dropped at t = 0. For subsonic perturbers, the isodensity contours are closed ellipsoids, which do no contribute to the drag force, except in the outer parts of the wake where the ellipsoids are
not closed. Supersonic perturbers generate a density wake only within the rear Mach cone. The gravitational
interaction with its own induced wake produces a drag force on the perturber. In this work, we revisit the
drag force on a non-accreting body. Our aim is to provide a physically more motivated and more insightful
formula for the drag force in the linear and nonlinear cases. Our analytical equation will be compared with
numerical simulations.
B
1
[email protected]
Instituto de Astronomı́a - UNAM
166
Short Talks
High Energy Astrophysics
HEAP-1
Time lags of the kilohertz quasi-periodic oscillations in the low-mass X-ray binaries 4U
1608-52 and 4U 1636-53
Marcio G B de AvellarB1 ; Mariano Méndez2 ; Andrea Sanna3 ; Jorge Horvath1
We studied the energy and frequency dependence of the Fourier time lags and intrinsic coherence of the
kilohertz quasi-periodic oscillations (kHz QPOs) in the neutron-star low-mass X-ray binaries 4U 1608-52
and 4U 1636-53, using a large data set obtained with the Rossi X-ray Timing Explorer. We confirmed that,
in both sources, the time lags of the lower kHz QPO are soft and their magnitude increases with energy. We
also found that: (i) In 4U 1636-53, the soft lags of the lower kHz QPO remain constant at ⇠ 30 µs in the QPO
frequency range 500-850 Hz, and decrease to ⇠ 10 mus when the QPO frequency increases further. In 4U
1608-52, the soft lags of the lower kHz QPO remain constant at 40 µs up to 800 Hz, the highest frequency
reached by this QPO in our data. (ii) In both sources, the time lags of the upper kHz QPO are hard, independent of energy or frequency and inconsistent with the soft lags of the lower kHz QPO. (iii) In both sources
the intrinsic coherence of the lower kHz QPO remains constant at ⇠0.6 between 5 and 12 keV, and drops to
zero above that energy. The intrinsic coherence of the upper kHz QPO is consistent with being zero across
the full energy range. (iv) In 4U 1636-53, the intrinsic coherence of the lower kHz QPO increases from ⇠0 at
⇠600 Hz to ⇠1, and it decreases to ⇠0.5 at 920 Hz; in 4U 1608-52, the intrinsic coherence is consistent with
the same trend. (v) In both sources the intrinsic coherence of the upper kHz QPO is consistent with zero
over the full frequency range of the QPO, except in 4U 1636-53 between 700 and 900 Hz where the intrinsic
coherence marginally increases. We discuss our results in the context of scenarios in which the soft lags are
either due to reflection off the accretion disc or up-/down-scattering in a hot medium close to the neutron
star. We finally explore the connection between, on one hand the time lags and the intrinsic coherence of
the kHz QPOs, and on the other the QPOs’ amplitude and quality factor in these two sources.
B
1
2
[email protected]
Departamento de Astronomia, Geofı́sica e Ciências Atmosféricas da Universidade de São Paulo
Kapteyn Astronomical Institute - University of Groningen
167
High Energy Astrophysics
Short Talks
HEAP-1
Unveiling the nature of an ultra-luminous X-ray source through the kinematics and
structure of its optical counterpart
Fuentes-Carrera, I.B1 ; Rosado, M.2 ; Arias, L.3 ; Moreno-Mendez, E.2 ; Borissova, J.4 ; Flores, H.5 ; Goncalves, D.6 ;
Salinas, A.1
With luminosities between 1039 - 1041 erg/s in the 0.5-10 keV band, ultra-luminous X-ray sources (ULXs) lie
between classic X-ray binaries and active galactic nuclei, and their nature is still far from clear. Current models include accreting stellar black holes (BHs) with strongly beamed emission, super-Eddington accretion in
stellar-mass BHs, extremely energetic supernovae, hypernovae, or intermediate-mass black holes (IMBH).
We present observations of the extended optical counterpart of the bright ULX in the S+S interacting galaxy
pair NGC 5953/54 using the FLAMES-GIRAFFE integral field spectrograph in its ARGUS mode in order to derive detailed spectroscopical and spatial information of the surroundings of this apparently elongated ULX.
The kinematics of the extended counterpart of this ULX and nature of the ionization of the gas is analysed in
the light of the different scenarios. Along with IFU observations we present long-slit observations taken with
the OSIRIS spectrograph on the Gran Telescopio de Canarias (GTC), near the location of the ULX and along
the star-forming region that seems to be enhanced by the interaction between the two galaxies in search of
peculiarities that could be associated with the origin of this energetic source.
B
1
2
3
4
5
6
[email protected]
Escuela Superior de Fisica y Matematicas, Instituto Politecnico Nacional, Mexico
Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Mexico
Universidad Iberoamericana, Mexico
Universidad de Valparaiso, Chile
Observatoire de Paris-Meudon, France
Observatorio do Valongo, Brazil
168
Short Talks
High Energy Astrophysics
HEAP-2
Mass and energy of GRB-SN events: multi-wavelength analysis of three associations in
the context of the full sample
Olivares E., F.B1,2 ; Greiner, J.1 ; Schady, P.1 ; Klose, S.3 ; Krühler, T.4 ; Rau, A.1 ; Savaglio, S.1 ; Kann, D. A.3 ; Pignata, G.2 ;
Elliott, J.1 ; Rossi, A.3 ; Nardini, M.5 ; Afonso, P. M. J.6 ; Filgas, R.7 ; Nicuesa Guelbenzu, A.3 ; Schmidl, S.3 ; Sudilovsky, V.1
After the discovery of SN 1998bw associated with GRB 980425, the first connection between Gamma-Ray
Bursts (GRBs) and Supernovae (SNe) occured almost 15 years ago, no more than two dozens SN-like rebrightenings and seven solid spectroscopically-confirmed associations have been observed to date. In this talk we
present data from the Gamma-Ray Burst Optical and Near-infrared Detector (GROND) and from the Swift
X-Ray Telescope (XRT) and Ultra-Violet/Optical Telescope (UVOT) for three GRB afterglows showing SN rebrightenings. We studied the luminosity and evolution of each GRB-SN event and derived accurate values of
the host-galaxy extinction through the modelling of the broad-band afterglow spectral energy distribution.
After correcting for all sources of foreground extinction, SNe 2009nz (associated with GRB 091127), 2010ma
(GRB 101219B), and 2008hw (GRB 081007), exhibited 1.15 ± 0.09, 1.78+0.08
0.17 , and 0.80 ± 0.10 times the luminosity of SN 1998bw, respectively. After subtracting the afterglow component, we constructed quasi-bolometric
light curves and modelled them using Arnett’s analytical approach to obtain the physical parameters of the
SN explosion, such as synthesised
56
Ni mass (MNi ), ejecta mass (Mej ), and kinetic energy (Ek ). From the
full sample of 29 GRB-SNe, the largest ever presented, we utilised the SN and GRB parameters to assess the
nature of the connection statistically. The average brightness for 27 GRB-SNe corresponds to an absolute
magnitude of MV =
19.46(±0.12 RMS), where only 7% of all GRB-SNe are significantly brighter than SN
1998bw. Two populations are identified in the MNi -Mej plane. We attribute this bimodality to two mass-loss
scenarios distinguished mainly by how much mass was lost at late evolutionary stages. Moreover, marginal
anti-correlations are found between GRB isotropic energy release E
,iso
and Ek from the SN, however, we
show that the GRB and SN energetics are decoupled overall. The data suggest a preference for SN events to
be on average associated with soft low-luminosity, however, this can be explained by selection effects solely.
B
1
2
3
4
5
6
7
[email protected]
Max-Planck-Institut fur extraterrestrische Physik, Giessenbachstraße 1, 85740 Garching, Germany
Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago, Chile
Thüringer Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany
Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen, Denmark
Università degli studi di Milano-Bicocca, Piazza della Scienza 3, 20126, Milano, Italy
American River College, Physics and Astronomy Dpt., 4700 College Oak Drive, Sacramento, CA 95841, USA
Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, 12800 Prague 2, Czech Republic
169
High Energy Astrophysics
Short Talks
HEAP-2
Runaway massive stars as a new class of galactic gamma-ray sources
del Valle, M. V.B1 ; Romero, G. E.1
Runaway stars have high spatial velocities, V > 30 km s
1
, and if the are massive, can produce bowshocks
in the surrounding ISM. These bowshocks develop as arc-shaped structures pointing in the same direction
as the supersonic stellar velocity. The piled-up shocked matter emits thermal radiation. Additionally, a population of locally accelerated relativistic particles can produce non-thermal emission over a wide range of
energies. This has been recently confirmed by a bunch of observations at radio, X-ray and even gamma-ray
wavelengths. Runaway early-type stars might be variable gamma-ray sources, with variability time scales
depending on the scales of density inhomogeneities in the medium and the stellar velocity. Protons can
easily escape from the emitting region without much loss on energy. These protons might diffuse in the surrounding molecular cloud interacting with the matter via p-p inelastic collisions. These yield gamma rays
and secondary particles. Molecular clouds illuminated by these relativistic particles might become into diffuse non-thermal sources. We calculate all relevant non-thermal processes related to these stellar objects
and discuss the observational prospects.
B
1
[email protected]
Instituto Argentino de Radioastronomia (IAR)
170
Short Talks
High Energy Astrophysics
HEAP-2
Spectral analysis of type II Supernovae
B1
Claudia P. Gutiérrez
; Joseph P. Anderson1 ; Mario Hamuy1 ; Santiago Gonzalez-Gaitán1 ; Gastón Folatelli2 ; CSP team3
We present a spectroscopic analysis of the H↵ profiles of hydrogen-rich type II supernovae. A total of 56 type
II supernovae were analyzed concentrating on the H↵ P-Cygni profiles. Expansion velocities and the ratio of
absorption to emission (a/e) at the epoch of transition between initial and plateau decline phases in the light
curve are defined to describe the diversity in this line. These spectral properties are correlated with photometric properties: absolute magnitudes, decline rates and the optically thick duration phase. Testing the
strength of various correlations we find that a/e appears to be the dominant parameter in terms of describing the diversity in our measured supernovae properties. It is found that supernovae with smaller a/e have
higher H↵ velocities, more rapidly declining light-curves from maximum, during the ‘plateau’ and radioactive tail phase, are brighter at maximum light and have smaller optically thick duration values. We discuss
possible explanations of these results in terms of physical properties of type II supernovae, speculating that
the most likely parameters which influence the morphologies of H↵ profiles are the mass and density profile
the hydrogen envelope, together with extra emission components due to circumstellar interaction.
B
1
2
3
[email protected]
Departamento de Astronomia, Universidad de Chile
Institute for the Physics and Mathematics of the Universe (IPMU) University of Tokyo
Carnegie/Las Campanas Observatories
171
High Energy Astrophysics
Short Talks
HEAP-2
Astronomy and Astrophysics in the Colombian Andes: the PAS Project
Asorey, H.B1,2 ; Núñez, L. A.1
The PAS (Polo de Astronomı́a Social) project aims to establish a permanent link, a bridge, between science
and society. This project is focused on building an astrophysical touristic center at the north eastern region
of the Colombian Andes.
Two 12-meter hemispheric domes will allocate the scientific and outreach installations. In one of them,
the ”Science dome”, a 20r̈obotic telescope will be installed, and would be controlled remotely. In this first
dome, offices, laboratories and data acquisition, simulation and distribution mainframes will be operated.
All the collected data will be available trough a collaborative framework that allow to register, to catalog, to
analyze and to share the obtained results. In the second dome, the ”Society dome”, a planetary system and
a convention center will be builded, with emphasis in the complex scientific data visualization capabilities
of this system. Both domes will be linked by a tunnel, the ”Science Tunnel”, which will be a conceptual
representation of this wanted bridge between science and society. In this tunnel, a complex visualization
wall will allow the visitors to share different interactive experiences. Outreach activities, such as the ”Stars
Camping Weekend”, are being planned.
Due to its geographic characteristics, the Andinian Páramo located near Berlı́n, Colombia, at 3500 m a.s.l.,
is an excellent location to build an array of particle detectors to study cosmic rays in a wide energy range,
including solar activity modulation of cosmic rays, gamma ray bursts (GRB), and the high energy region of
the cosmic rays spectrum. The proposed array will consist in more than one hundred of autonomous and
wireless water Cherenkov detectors (WCD) located over different concentric triangular grids with different
spacing between neighbor detectors, spanning over a total area of more than 16 km2 . This facility will be
operated by an international and interdisciplinary group of researchers.
The design of the detector array is based on Corsika air showers and Geant4-based detector response
simulations. The proposed design of this array will allow to implement two different measurement modes:
the counting mode and the shower mode. In the counting mode, the variations in the recorded flux of secondary particles at detector level can be correlated with transient phenomena, such as the solar modulation
of galactic cosmic rays or the arrival of the highest energy component of an energetic GRB; or long term
flux modulations related, e.g., with the solar activity cycle. In the shower mode, in contrast, we will look for
time-space correlated signals in different, non-aligned, detectors of the array. In this way, it will be possible
to determine the main parameters that characterize the extensive air shower (EAS) produced by the interaction of a single high-energy cosmic ray with the atmosphere. From this parameters, the arrival direction and
the energy of the impinging cosmic ray will be obtained. The size of the array and the increasing spacing between detectors will allow to complement present measurements in the so called knee region of the cosmic
ray energy spectrum (E ⇠ 1015 eV) and beyond.
In this work, we show the present status of the design of this facility, its academic and social goals and its
scientific capabilities are presented.
B
1
2
[email protected]
Escuela de Fı́sica, Universidad Industrial de Santander, Bucaramanga, Colombia
Centro Atómico Bariloche and Instituto Balseiro (CNEA, UNCuyo, CONICET), San Carlos de Bariloche, Argentina
172
Instrumentation
INST-1
LLAMA Project
B1
E. M. Arnal
2
; Z. Abraham ; G. Giménez de Castro3 ; E. M. de Gouveia dal Pino2 ; J. J. Larrarte4 ; J. Lepine2 ; R. Morras1 ;
J. Viramonte5
LLAMA, acronymum of Long Latin American Millimetre Array, is a joint scientific and technological undertaking of Argentina and Brazil whose main goal is to install and to operate a 12m dish capable of studying
the Universe at millimetre and sub-millimetre wavelengths.
This facility will be erected in the norwestern part of Argentina, some 20 km away from the town of San
Antonio de los Cobres (Salta province), at a site located 4830m above sea level.
In this presentation we would like to formally introduce this project to the Latin American astronomical
community by briefly describing its current status.
Besides working as a stand alone instrument (or single dish mode), this radiometer may also become part
of a local network of Very Long Baseline Interferometry (VLBI) that may be integrated by existing telescopes
like APEX, ASTE, Itapetinga and some of the ALMA dishes. In its way, this VLBI network may be able to
increase the resolving power of ALMA by an order of magnitude.
The construction phase of this facility is being financed by Ministerio de Ciencia, Tecnologı́a e Innovación
Productiva (MINCyT, Argentina) and Fundação de Amparo á Pesquisa do Estado de São Paulo (FAPESP), on
the basis of an equal investment share.
B
[email protected]
Instituto Argentino de Radioastronomia (IAR), CCT-La Plata, CONICET and Facultad de Ciencias Astronómicas y Geofı́sicas, Universidad Nacional de La Plata, Argentina
2 Instituto de Astronomia e Geofisica, Universidad de San Pablo, Brazil
3 CRAAM, Universidad Presbiteriana Mackenzie, San Pablo, Brazil
4 Instituto Argentino de oéomia, Radioast (IAR), CCT-La Plata, CONICET
5 Instituto Geonorte, CONICET-UNSa, Argentina
1
173
Instrumentation
Short Talks
INST-1
SOUTH POL: Revealing the Polarized Southern Sky
Magalhães, A. M.B1
SOUTH POL will be a survey of the Southern sky in optical polarized light. It will use a newly designed
polarimeter for an 80cm Robotic Telescope. Telescope and polarimeter will be installed at CTIO, Chile. The
initial goal is to cover the sky south of declination
15 in about two years of observing time, aiming at a
polarimetric accuracy  0.1% down to V=15, with a camera covering a field of about 2.0 square degrees.
SOUTH POL will impact areas such as Cosmology, Extragalactic Astronomy, Interstellar Medium of the
Galaxy and Magellanic Clouds, Star Formation, Stellar Envelopes, Stellar Explosions and Solar System, among
others.
The polarimeter is currently being built and its optics and electronics assembled. We will describe the
current status of the project.
This project is supported by FAPESP. AMM is also supported by CNPq.
B
1
[email protected]
Departamento de Astronomia, IAG, Universidade de São Paulo
174
Short Talks
Instrumentation
INST-1
The hard X-ray telescopes for MIRAX and protoMIRAX
B1
Braga, J.
; D’Amico, F.1 ; Ávila. M. C.1 ; Rodrigues, B. H.1,2 ; Grindlay, J. E.2 ; Allen, B.2 ; Hong, J.2 ; Barthelmy, S.3 ;
Rothschild, R. E.4
The Monitor e Imageador de Raios X (MIRAX), under development at the National Institute for Space Research (INPE), Brazil, is a hard X-ray astronomy experiment that will be launched in low-Earth orbit (650 km
altitude, 15 inclination) onboard the Lattes satellite mission in 2018. MIRAX consists essentially in two
coded-aperture imaging telescopes equipped with cadmium-zinc-telluride (CZT) solid-state room-temperature
semiconductor detectors. One telescope (T1) has been in development at INPE0 s Astrophysics Division and
will fly in a high altitude (⇠43 km) balloon in 2014 for testing and demonstration; this development is called
the protoMIRAX project. T1 uses an array of 13⇥13 CZT planar detectors with dimensions 10mm⇥10mm⇥2mm
and a 1 mm-thick lead coded mask with 20 mm openings in a 13⇥13 Modified Uniformly Redundant Array
(MURA) basic pattern. It will have a 20 ⇥ 20 fully-coded field-of-view (FCFOV) and an angular resolution
of 1.5 . T1 will be mounted in a balloon gondola with an attitude control and pointing systems as well as
a 500 kbps telemetry and command capability for real-time operation and data acquisition. The imaging
CZT detectors for the second telescope (T2) are being developed at the Harvard Smithsonian Center for Astrophysics (CfA). The detector plane for T2 will have a 0.6 mm spatial resolution and an area of 250 cm2 . A
0.3mm-thick tungsten mask with a random pattern will provide images with 60 angular resolution with a
20 ⇥ 20 FWHM FOV. In this presentation we will describe the current status of MIRAX and present results
of the protoMIRAX detector, telescope and balloon gondola developments.
B
1
2
3
4
[email protected]
Astrophysics Department, National Institute for Space Research, Brazil
Harvard Smithsonian Center for Astrophysics
NASA Goddard Space Flight Center
Center for Astrophysics and Space Science, University of California San Diego
175
Instrumentation
Short Talks
INST-1
Cherenkov Telescope Array (CTA)
Barres de Almeida, U.B1 ; De Gouveia Dal Pino, E.2
Gamma-ray astronomy holds a great potential for Astrophysics, Particle Physics and Cosmology. The CTA
is an international initiative to build the next generation of ground-based gamma-ray observatories, which
will represent a factor of 5-10x improvement in the sensitivity of observations in the range 100 GeV - 10 TeV,
as well as an extension of the observational capabilities down to energies below 100 GeV and beyond 100
TeV. The observatory consists of two telescope networks (one in the Northern Hemisphere and another in
the South, the latter with about 60 telescopes) so to achieve a full-sky coverage. It will grant open access to
the community, through call for submission of proposals competing for observation time. The CTA will give
us access to the non-thermal and high-energy universe, to a level never reached so far, and will be one of
the main instruments for high-energy astrophysics and astroparticle physics of the next 30 years. Brazil is a
member of the CTA consortium, and the project is represented in Latin America by Argentina and Mexico as
well. In this talk we will present the basic concepts of the CTA and the project of the observatory which is now
under development. Emphasis will be put on its scientific potential and on the Latin-American involvement
in the preparation and construction of the experiment. The CTA is expected to be fully operational by 2018,
and by the end of this year the site of installation of CTA should be defined. Among the most promising sites
for the southern array there are three South American candidates, two in Argentina and one in Chile.
B
1
2
[email protected]
Centro Brasileiro de Pesquisas Fı́sicas (CBPF/MCTI)
Instituto Astronômico, Geofı́sico e de Ciências Atmosféricas, Universidade de São Paulo (IAG/USP)
176
Short Talks
Instrumentation
INST-2
Observational Results using BTFi
Quint, B.B1 ; Mendes de Oliveira, C.1 ; BTFI Team
We present here an overview of a new tunable filter instrument for the SOAR telescope. The Brazilian Tunable Filter Imager (BTFI) is a highly versatile new technology to be used both in seeing-limited mode and
at higher spatial fidelity using SAM Ground-Layer Adaptive Optics facility (SOAR Adaptive Module) which
is being deployed at the SOAR telescope. It presents important new science capabilities for the SOAR astronomical community, from studies of the centers of nearby galaxies and the insterstellar medium to statistical
cosmological investigations. BTFI will deliver XY data-cubes that can be seen as set of images at different
wavelengths or a set of spectra for each XY pixel. For that, it relies on three new technologies. The imaging
Bragg Tunable Filter (iBTF) concept utilizes Volume Phase Holographic Gratings in a double-pass configuration as a tunable filter, while a new Fabry-Perot (FP) concept involves the use of commercially available
technologies which allow a single FP etalon to act over a very large range of interference orders and hence
spectral resolutions. Both of these filter technologies will be used in the same instrument. The combination allows for highly versatile capabilities. Spectral resolutions spanning the range between 25 and 2000
can be achieved in the same instrument through the use of iBTF at low resolution and scanning FPs beyond
R ⇡ 2000 with some overlap in the mid-range. The third component of the new technologies deployed in
BTFI is the use of EMCCDs, which allow for rapid and cyclical wavelength scanning thus mitigating the damaging effect of atmospheric variability through the acquisition of the data cube. The system was designed to
supply tunable filter imaging with a field-of-view of 3’ on a side, sampled at 0.12” for direct Nasmyth seeinglimited area spectroscopy and for SAM’s visitor instrument port for GLAO-fed area spectroscopy. The final
data-cube is obtained throught scanning in wavelength while acquiring images, stacking these images together and processing this stack thoght software so the cube has XY information. The instrument has been
already tested on sky and we are presenting observational data of the planetary nebulae NGC 7009 in high
resolution mode and NGC 2440 in low resolution. For high resolution, we used a QueensGate Fabry-Perot
installed inside BTFi with R = 4500 while, for low resolution, the iBTF was used with R = 1200 gratings, both
near H-alpha.
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1
[email protected]
IAG/USP
177
Instrumentation
Short Talks
INST-2
BOMBOLO: a Multi-Band, Wide-field, Near UV/Optical Imager for the SOAR 4m
Telescope
Angeloni, R.B1,2,3 ; Guzman, D.2 ; Puzia, T. H.1 ; Infante, L.2 ; Kanaan, A4 ; Oliveira, C.5 ; et al.
In this contribution I will present BOMBOLO, a new astronomical multi-passband instrument proposed for
the SOAR 4m Telescope. As the first Chilean instrument of its kind, it is a three-arms imager covering the
near-UV and optical wavelengths. The three arms work simultaneously and independently, providing synchronized imaging capability for rapid astronomical events. BOMBOLO will be able to address largely unexplored events in the minute-to-second timescales, with the following leading science cases: 1) Simultaneous
Multiband Flickering Studies of Accretion Phenomena; 2) Near UV/Optical Diagnostics of Stellar Evolutionary Phases; 3) Exoplanetary Transits; 4) Microlensing Follow-Up; 5) Solar System Studies. BOMBOLO has
been approved by the SOAR Board of Directors as a visitor instrument.
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1
2
3
4
5
[email protected]
Instituto de Astrofı́sica, Pontificia Universidad Católica de Chile - Santiago, Chile
Centro de Astro-Ingenierı́a, Pontificia Universidad Católica de Chile - Santiago, Chile
The Milky Way Millennium Nucleus, Santiago, Chile
Physics and Astronomy Dept., University of Santa Catarina, Brazil
Astronomy, Geophysics & Atmospheric Sciences, University of Sao Paulo, Brazil
178
Short Talks
Instrumentation
INST-2
New algorithm for centroiding in elongated Shack-Hartmann wavefront sensors spots
using artificial neural networks
Mello, A. T.B1 ; Kanaan, A.1 ; Guzman, D.2 ; De Cos, F. J.3
To recover the resolution lost in a ground-based telescope due to the atmosphere, it is necessary to use a
technique known as Adaptive Optics (AO). The next generation of telescopes will have primary mirrors of
more than 25 meter in diameter and will require AO systems from the ground up. There are a number of
challenges to implement an AO system at these scales. One of these challenges is the accurate measurement
of the aberrated wavefronts using a laser guide star and a Shack-Hartmann wavefront sensor. Due to the
diameter of the telescope and the use of the Sodium layer in the upper atmosphere as photon return for
the laser guide stars, the image of the guide star will appear elongated in the wavefront sensor. Typical
centroiding algorithms such as Center of Gravity do not perform well under these conditions. This article
presents a new technique based on artificial neural networks for measuring the spot position with better
accuracy than existing methods. Simulation results will confirm that the new algorithm incurs in smaller
errors with respect to other centroiding techniques in use.
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1
2
3
[email protected]
Universidade Federal de Santa Catarina, Brazil
Pontificia Universidad Catolica de Chile
Universidad de Oviedo, España
179
Instrumentation
Short Talks
INST-2
GeMS/GSAOI: from commissioning to operations and science results
E. R. CarrascoB1 ; B. Neichel1 ; F. Rigaut2 ; C. Winge1 ; F. Vidal1 ; P. Pessev1 ; A. Serio1 ; G. Arriagada1 ; W. Rambold1 ; J. Luhrs1 ;
M. Boccas2 ; C. Dorgeville2 ; V. Fesquet1 ; A. Lopez1 ; C. Trujillo3 ; R. Galvez1 ; G. Gausachs1 ; C. Araujo1 ; T. Vucina1 ;
V. Montes1 ; C. Urrutia1 ; C. Moreno1 ; C. Marchant1 ; F. Collao1 ; S. Diggs1 ; F. Collao1 ; G. Trancho4 ; M. Bec4
The Gemini Multi-conjugate Adaptive Optics System (GeMS) and the Gemini South Adaptive Optics Imager
(GSAOI) are unique and complex facility Gemini instruments. GeMS/GSAOI provide a uniform, diffraction
limited image quality at near-infrared (NIR) wavelengths over a field of view of 85” x 85” on the sky. The
GeMS/GSAOI commissioning started at the beginning of 2011. After ⇠2 years of dedicated work and more
than 90 nights of on-sky commissioning, at the end of 2012 GeMS/GSAOI started to produce the first science
results. In this presentation we describe in details the system performance, on-sky efficiency and present
the scientific results produced by GeMS/GSAOI during the system verification process.
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1
2
3
4
[email protected]
Gemini Observatory/AURA, Southern Operations Center
Research School of Astronomy and Astrophysics, The Australian National University
Gemini Observatory/AURA, Northern Operations Center
Giant Magellan Telescope Organization
180
Short Talks
Instrumentation
PS -3
Solar astrometry and the heliometer of Rio de Janeiro
Sigismondi C.B1,4 ; Boscardin S. C.1 ; Andrei A. H.1,2,3 ; Reis Neto E.5 ; Penna J. L.1 ; D’Avila V. A.1,6
Three quantities characterize the state of a self gravitating gaseous body: pressure, temperature and volume,
but the radius is the only one directly measurable for the Sun, what is specially true in the optical window
and for ground-based measurements. The Heliometer of the Observatório Nacional, in Rio de Janeiro, measures the distance between two opposite limbs of the Sun in the same field of view, through the reflection
on a 10 cm parabolic mirror split on its half and forming an appropriate angle. This configuration is free
from optical aberrations and focal variations along the measurement direction. The mirrors are made on
CCZ vitro-ceramic and the telescope structure is of carbon fiber, resulting that there is no flexion or temperature deformation. The instrument is compact, and it can perform hundreds of measurements per duty
day, around all heliolatitudes. Vertical and horizontal differential refractions to the solar image and their
dependance on air pressure, temperature and water vapour content are taken into account for data reductions: they are minimum when the center of the Sun approaches the zenith as this is verified for more than
a month in Rio de Janeiro. The heliometer attains an accuracy on the solar radius of 0.01 arcsec, becoming
the ideal instrument to monitor the solar diameter from the ground, and to bridge satellites and astrolabes
historical series of data. We discuss the first years of regular observation, with emphasis on the instrumental
calibrations and on the statistic study of the derived time series and solar geometry series. On basis of these
analysis we obtain how well the Heliometer and Solar Astrolabe results are matched, extending a continuous
solar semi diameter series over forty years.
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1
2
3
4
5
6
[email protected]
Observatório Nacional/MCTI
Observatório do Valongo/UFRJ
SYRTE/Observatoire de Paris
ICRANet/Sapienza Universitá di Roma and Ateneo Pontificio Regina Apostolorum
MAST/Museu de Astronomia e Ciências Afins/MCTI
UERJ/Universidade do Estado do Rio de Janeiro
181
182
Teaching & Outreach
TO -1
Assessing and evaluating: a case study in the framework of EU-UNAWE Italy project
Lara AlbaneseB1 ; James Bradburne2 ; Alessandra Zanazzi1
A special case study evaluation will be presented, relative to a whole year work in the framework of EU UNAWE Italy, with teachers in training sessions and in the classrooms, children, and parents also. When it comes
to activities with children or very young children, evaluation and assessment needs to be comprehensive and
take into account different aspects such as parents involvement, spontaneous interest and spontaneous play,
curiosity and awareness. In such a context, it assumes a huge importance to acquire a varied and exhaustive
documentation, that could possibly give the chance of reflecting, registering and also quantifying the goals
that have been reached and the achievements, also in following steps and after the activities ended. The
goals are not only those regarding a cognitive level, but involve all the possible “languages” of the child; in
particular they are connected to the child imagery.
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1
2
[email protected]
INAF - OSSERVATORIO ASTROFISICO DI ARCETRI
FONDAZIONE PALAZZO STROZZI, FLORENCE
183
Teaching & Outreach
Short Talks
TO -1
Life in the Cosmic Context. An Astrobiology Course as an Experiment in
Transdisciplinarity
Amancio Cesar Santos FriaçaB1 ; Eduardo Janot Pacheco1
Astrobiology is a new interdisciplinary field of research concerned with the study of the origin, distribution,
and destiny of life in the universe. It is rapidly gaining the attention of scientists and the public. The appeal
of astrobiology is due to the fundamental questions it poses: what is life? are we alone in the universe? what
will be the future of life on Earth and elsewhere? In 2003, University of São Paulo (USP) created the course of
astrobiology “Life in the Cosmic Context”, addressing these questions taking into account several disciplines
– astrophysics, biology, chemistry, geology, meteorology, environmental sciences. The course is provided by
IAG (Instituto de Astronomia, Geofı́sicas and Ciências Atmosféricas) to undergraduate students of science
and humanities majors. The fact that a large number of majors is represented in the course illustrates the
capability of astrobiology in integrating several fields of knowledge. The central underlying questions are
explored in class by a wide variety of activities designed to build a transdisciplinary frame. At the same time
that the course focuses on issues related to the idea of extraterrestrial life, the reflections and activities of the
students leads them to broaden their conceptions about life and to bridge disciplinary barriers. In this work,
we present some learning activities done during during the classes and the students feedback. Nearly 1,500
students have attended the “Life in the Cosmic Context” and we chart their impact in teaching and outreach
and their role in promoting the scientific literacy.
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1
[email protected]
IAG-USP
184
Short Talks
Teaching & Outreach
TO -1
“Planetário e Teatro Digital Johannes Kepler” and its Institutional Pedagogical Project
Faria, R. Z.1 ; Calil, M. R.B1 ; Perez, E. R.1 ; Kanashiro, M.1 ; Silva, L. C. P.1 ; Calipo, F.1
This work relates the reception of schools, started on August 2012, in the astronomic laboratory of the
“Planetário e Teatro Digital Johannes Kepler”, located in the “Sabina - Escola Parque do Conhecimento”
in Santo André, São Paulo. The idealization of this project, authorship of Marcos Calil, PhD, consists in
four apprenticeship environments disposed around the planetary dome. They make reference to the System Sun - Earth - Moon (Tellurium), Solar System, Astronautic and Stars. On Tuesdays and Wednesdays
the astronomic laboratory is used by Santo André municipal schools for focused lessons, being possible on
Thursdays scheduling for private and public schools. On weekends and holidays is opened for the visitors.
Since the inauguration to the beginning of activities with students, the monitor team was guided and trained
on contents of Astronomy and Aeronautic to execute the schools service. This is done in four stages, which
are: reception, course trough the astronomic laboratory, dome session and activities closure. During the
reception the acquaintance rules are passed on for a better visit. Before starting the course the monitors
do a survey about the previous knowledge of the students. On the astronomic laboratory resources of the
environment are used to explain the contents of Astronomy and Astronautic, always considering the age
group and the curriculum developed in classroom. After the course the students watch a planetary session
supporting the contents seen on the astronomic laboratory. At the end a feedback is done with the students
about the subject discussed. During the visit the teachers fulfill an evaluation about the place and the service. From August 2012 to November 2012 were attended between municipal, public and private schools.
From the 4932 students attended, 92% belonged to the municipal network, 5% to the private network and
3% to the public network. From the 189 evaluations done by the teachers, 97.8% were satisfied, 2.1% partially
satisfied e 0.1% unsatisfied with the reception promoted by the team of the planetary. Meantime the satisfaction presented on the evaluation is thought that the use of non-formal places is an ally of apprenticeship.
The “Planetário e Teatro Digital Johannes Kepler” by its team collaborates for an education and divulgation
of the Astronomy and Astronautic make part of the reality and quotidian of the students of the city of Santo
André.
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1
[email protected]
Theatre Digital and Planetarium Johannes Kepler
185
Teaching & Outreach
Short Talks
TO -1
Brazilian Participations in the International Astronomical Search Collaboration
Rojas, G. A.B1 ; Dalla-Costa, L. J.; Kalmus, A. T.; Kroth, E. C.; Matos, M. F.; Silva, A. L.; Silva, G. G.
International Astronomical Search Collaboration (IASC) is an international educational project between universities, schools, observatories and research institutions. Its main objective is to enroll high school and
college students in the monitoring and discovery of asteroids and Near Earth Objects (NEOs), especially Potentially Hazardous Asteroids. The methodology consists in the analysis of astronomical images obtained
in several observatories in North America and Hawaii. The images are distributed throughout the school
network and the results must be delivered in a 72-hour timeframe. Since 2010 Brazilian universities and
schools have joined IASC, resulting in over a dozen new asteroids found (3 of them NEOs), and hundreds of
measurements for already known asteroids. A major event in this collaboration was the All-Brazil Asteroid
Search Campaign, which was conducted in September 2012. 2013 marks the fourth year of Brazilian participations in IASC, with one important milestone: the third straight appearance of a Brazilian institution in the
Pan-STARRS campaign, which uses the PS1 telescope in Haleakala, Hawaii. We will present a summary of
the overall results, as well as the latest news from 2013 campaigns. We will discuss the impact promoted by
the past events, such as how the interest in astronomy changed before and after the campaigns, and it has
helped the students to choose their future careers.
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1
[email protected]
Universidade Federal de São Carlos, Brazil
186
Short Talks
Teaching & Outreach
TO -1
Alfabetización en Astronomı́a de docentes de Educación Primaria y de Educación
Secundaria en La Plata
De Biasi, M. S.B1 ; Orellana, R. B.1
La educación de este siglo tiene como uno de sus retos alcanzar la alfabetización cientfica de todos los ciudadanos para que comprendan y tomen decisiones sobre el mundo natural y sus cambios originados por
la actividad humana utilizando el conocimiento cientı́fico. En esta misión los docentes de los niveles obligatorios de enseñanza juegan un papel clave por su rol de agentes multiplicadores del conocimiento. Se
requiere, entonces de una adecuada alfabetización en ciencias de los docentes o, como mı́nimo, que dominen los temas cientı́ficos a enseñar.
En el campo de la Astronomı́a, numerosas investigaciones han señalado que maestros de primaria y estudiantes de profesorados poseen una escasa formación en estos temas (Camino 1995 y 1999, Gangui 2010),
que frecuentemente presentan a los alumnos concepciones alternativas o no cientı́ficas de los fenómenos
astronómicos cotidianos (Kriner 2004, Vega Navarro 2007, Gangui et al 2010); a lo que se suma la presentación confusa o errónea de algunos temas astronómicos en los textos escolares (Kriner 2004).
Desde 2011, la Facultad de Ciencias Astronómicas y Geofı́sicas, UNLP, ofrece un curso de capacitación
destinado a fortalecer y actualizar los contenidos académicos y didácticos de los docentes del distrito La
Plata utilizando diversas estrategias didácticas. Los contenidos comprenden los temas astronómicos de los
diseños curriculares vigentes.
La evaluación diagnóstica de los conocimientos previos de los docentes cursantes sobre los contenidos
de mayor presencia en los diseños curriculares mostró resultados similares a las investigaciones arriba mencionadas. Referente a los movimientos de la Tierra, en promedio, el 54% poseı́a conceptos erróneos y el 16%
no los sabı́a; con referencia a la Luna el 56% poseı́a conceptos erróneos y un 4% no los sabı́a. Los resultados
del curso mostraron que el 95% de los docentes revirtió sus conceptos previos erróneos, que adquirió criterios para la búsqueda de fuentes de información confiables y que el grado de conocimientos disciplinares y
didácticos alcanzados por los docentes garantiza el efecto multiplicador de esta propuesta.
Esta capacitación fue acreditada con puntaje por el organismo educativo provincial en 2011, 2012 y 2013.
B
mariasilvina [email protected]
Facultad de Ciencias Astronómicas y Geofı́sicas, UNLP, Paseo del Bosque s/n, 1900, La Plata, Argentina e Instituto de Astrofı́sica de La
Plata (CCT La Plata - CONICET, UNLP)
1
187
Teaching & Outreach
Short Talks
TO -2
The IAU Office of Astronomy for Development: Opportunities for Latin America
Kevin GovenderB1
In 2009, the IAU General Assembly approved a strategic plan to use astronomy as a tool for global development. Soon afterwards the IAU established its Office of Astronomy for Development (OAD) to realise a vision
of ”Astronomy for a better world.” Since 2011 the OAD has established two regional offices and released two
open calls for proposals. This presentation will discuss these and other activities of the OAD, specifically in
the three focus areas of (i) universities and research; (ii) children and schools; and (iii) public outreach. The
presentation will also focus on opportunities available for Latin America both in terms of developing the
astronomy field and also using astronomy to stimulate development in the region.
B
1
[email protected]
IAU Office of Astronomy for Development
188
Short Talks
Teaching & Outreach
TO -2
The GalileoMobile Project
1
2
3
Benı́tez, S. ; Bhatt, M. ; Bonoli, S. ; Bühler, D.1 ; Canas, L.4 ; Candelaresi, S.5 ; Dası́ Espuig, M.1 ; Gomes, N.6 ; Joshi, J.1 ;
Kobel, P.7 ; Penteado, E. M.8 ; Rivero González, J.9 ; Schoenell, W.10 ; Silva, P. B.4 ; Sordo, F.5 ; Spinelli, P. F.B11 ; Strubbe, L.12 ;
Varguez, M.13 ; Vasquez, M.14
GalileoMobile is a traveling science education project by an international team of PhD students, recent graduates and science communicators (partnering with the Universe Awareness program) that brings astronomy
to young people in regions where outreach science programs are a rare opportunity. Our primary project
goals are: (1) to stimulate students’ curiosity and interest in learning, (2) to exchange different visions of the
cosmos and cultures, and (3) to inspire a feeling of unity ”under the same sky” between people from different
parts of the world. In 2009, GalileoMobile traveled to 30 schools in Chile, Bolivia and Peru, bringing handson activities and Galileoscopes; the team also produced a documentary movie to share the experiences and
culture with the world. In 2012 the team accomplished two new expeditions, visiting 12 villages in the Indian
state of Karnataka and 5 communities in the Bolivian Amazon. In 2013, GalileoMobile is heading to Uganda
to a twelve-day trip (september 2013) to work in schools and villages. In these talk, I will briefly introduce
the GalileoMobile project, review our methods and outcomes in the countries the project have visited and
provide an outlook of our upcoming 2014 Brazil-Boliva (BraBo) expedition.
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[email protected]
Max Planck Institute for Astrophysics
2 Max Planck Institute for Solar System
3 University of Zurich
4 Navegar Foundation, Centro Multimeios de Espinho
5 Nordic Institute for Theoretical Physics
6 European Southern Observatory
7 École Polytechnique Fédérale de Lausanne
8 Institute for Molecules and Materials
9 University Observatory Munich
10 Instituto de Astrofı́sica de Andalucı́a
11 Museu de Astronomia e Ciências Afins
12 Canadian Institute for Theoretical Astrophysics
13 Humanistic Studies in Science and Culture of Monterrey Institute of Technology and Higher Education
14 Ferman Aerospace Center
1
189
Teaching & Outreach
Short Talks
TO -2
IOAA 2012: The first scientific international olympiad in Brasil, opening doors for 2016
Thais Mothé-Diniz1 ; Albert Bruch2 ; Carlos Alexandre Wuensche3 ; Eugênio Reis Neto4 ; Josina Nascimento5 ; Jorge
CarvanoB5 ; Fernando Vieira6 ; Helio Jacques Rocha-Pinto1 ; Carlos Eduardo Quintanilha7 ; Jaime Fernando Villas da
Rocha8 ; João Batista Garcia Canalle9
The International Olympiad on Astronomy and Astrophysics (IOAA) is an international level astronomy competition for high school students aged below 20 years old, held annually since 2007. In the years between
2007 and 2011 it was hosted by the founding countries: Thailand, Indonesia, Iran, China and Poland, with
Brazil represented in all editions of the competition.
Between 2012, August 04 and 14, the IOAA was hosted by Brazil, in the cities of Vassouras and Barra do
Piraı́, in the state of Rio de Janeiro. Brazil hosted for the first time a scientific competition at an international
level. Twenty six countries from four continents were represented, doing the exams, performing tasks and
observations of the night sky, and experiencing the brazilian culture and hospitality. The VI IOAA counted
with the collaboration of dozens of enthusiastic people, young and not so young astronomers, professionals
and amateurs, volunteers, and people from many other areas of knowledge.
Public schools and the general public benefited from the competition through the various open or semiopen activities offered by partner institutes and universities. The public schools of Vassouras city and Vale
do Café region also benefited from the training on usage of the telescopes that were donated to them. The
6th IOAA organisation, with Vassouras Town Hall and partners, promoted activities opened to public during the IOAA, in the context of a ”Semana da Astronomia de Vassouras” (Vassouras Astronomy Week), with
expositions, talks, movies, cultural shows, and others. To teachers an EREA (Regional Meeting on Astronomy Education) was offered, a large meeting of teachers training organised by the Brazilian Olympiad on
Astronomy and Astronautics (OBA).
The Olympiad represents more than a competition among students, but also friendship, information
exchange and cooperation in astronomy education among astronomers. Moreover, it motivates the participating countries to hold their own national (and even regional) level astronomy competition, leading to the
popularisation of astronomy in their countries.
The aim of this work is to present the organisers’ view of the execution of the VI IOAA in Brazil, as well
as its consequences to the popularisation of sciences in the country through activities during the olympiad
and the parallel, subsequent and ongoing activities. A great amount of experience to be shared with others
was gained through the VI IOAA in Brazil in 2012. It is also considered a first step towards the realisation of
the idea to host a ”Knowledge Competition” in Brazil in 2016.
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1
2
3
4
5
6
7
8
9
[email protected]
UFRJ / Observatorio do Valongo - OV
MCTI / Laboratorio Nacional de Astrofisica - LNA
MCTI / Instituto Nacional de Pesquisas Espaciais - INPE
MCTI / Museu de Astronomia e Ciências Afins - MAST
MCTI / Observatorio Nacional - ON
Fundação Planetario do Rio de Janeiro
Agência Espacial Brasileira - AEB
Universidade Federal do Estado do Rio de Janeiro - UNIRIO
Universidade do Estado do Rio de Janeiro - UERJ
190
Short Talks
Teaching & Outreach
TO -2
The Latin American Journal of Astronomy Education (RELEA): contributions and
perspectives
Bretones, P. S.B1 ; Jafelice, L. C.2 ; Horvath, J. E.3
The goal of this work is to present an analysis of articles published by the Latin American Journal of Astronomy Education (RELEA) since its beginning (2004) to the present. We analyzed the 59 articles available on
the website of the journal (http://www.relea.ufscar.br), published in 15 issues. The articles were classified
by: year of publication, issue, author’s institutions, grade level, focus of the study and content. The results
show that the number of articles is still small - although the journal has been initially qualified as B3 within
the Journal Ranking scheme Qualis CAPES and in the latest ranking (current) advanced to the concept B1 in
the Qualis, it is too early to expect an increase in the number of articles submitted. Among the main factors
for the relatively low number of articles we can mention that the initially nominated Editorial Board did not
succeed in a proper dissemination of the journal and call for papers, the ongoing absence of a “critical mass”
of astronomy education researchers and the lack of publishing tradition in the area. Important aspects of the
writing of articles submitted are also discussed, such as refereeing, acceptance rate of articles, participation
of authors from countries other than Brazil and theoretical and methodological frameworks, as well as the
recent editorial restructuration of the international Editorial Board of the RELEA and the nomination of Associate Editors from Brazil. Concluding, it is possible to note the contribution to the field up to the moment
through citations in other works in the field. However, it is necessary to advance with regard to: publishing
more articles, articles from greater variety of Latin American countries, training of the community for a minimum quality of the writing of articles submitted for publication in a journal aimed at education research. In
this sense, additional analyses of the published papers would be desirable. Finally, it is pointed out the need
for greater dissemination of the journal to increase the number of submissions, encouraging the diversification of contents and methods and increase the participation of authors in general and from Latin America
in particular, aiming to greater academic contribution for astronomy education at various levels and places.
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1
2
3
[email protected]
DME, UFSCar
Depto. de Fı́sica, UFRN
IAG, USP
191
192
Posters
193
Planetary Systems
PS -1:
#1
Stellar occultation by the trans-Neptunian object 2002 KX14
A. Alvarez-CandalB1,2 ; J. L. Ortiz2 ; N. Morales2 ; R. Duffard2 ; S. Littlefair3 ; V. S. Dhillon3 ; B. Sicardy4 ; S. Mottola5 ;
S. Hellmich5 ; T. Marsh6 ; T. Shahbaz7
On the night of April 25, 2012 we observed a stellar occultation by the trans-Neptunian object (119951) 2002
KX14 . Astrometric predictions had shown that the shadow path would pass upon Earth’s north hemisphere
and was potentially favorable for the south of Europe and even the Canary islands. Several professional and
amateur telescopes/observers attempted to observe the event. We had a successful observation from the
4.2-m William Herschel telescope at the Roque de los Muchachos observatory, La Palma, Spain, where the
visiting instrument Ultracam was used.
The occultation light-curve has a depth of 1.98 mag and lasted 21.2 s, this implies a minimum diameter
of (414 ± 4) km. There is no evidence of atmosphere from the light-curve.
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1
2
3
4
5
6
7
[email protected]
Observatório Nacional
Instituto de Astrofı́sica de Andalucı́a
University of Sheffield
LESIA/Observatoire de Paris
DLR/German Aerospace Center Institute of Planetary Research
Department of Physics, University of Warwick
Instituto de Astrofı́sica de Canarias
195
Planetary Systems
Posters
PS -1:
#2
Rotation of Multi-layered Super-Earths
Nelson Callegari Jr.B1
Super-Earths are planets with possible terrestrial-like composition and mass compared to the Earth mass.
Many numerical studies on internal structure of these planets show a diversity of differentiation whose configuration depends on the mass of the planet, the initial composition of each layer before the reaching of
the equilibrium, densities and other parameters. Due to the fact that several of these planets have compact orbits with orbital period with order of magnitude of days or less, some works have shown recently the
complexity of dynamics of rotation of some of them, as is the case of 55 Cnc e. In the referred papers, it
is considered a single homogeneous planet. In view of the multi-layered models of Super-Earths, a more
complete model of rotation of the planet, characterized by the motion of the outer layer, can be done. In
this work we show an improvement of the homogenous model on the basis of the efforts which consider
gravitational coupling between the solid-like layers of planets or regular satellites. The main motivations of
these works are theoretical modeling the mantle-inner core torque coupling of the Earth. We have prepared
a numerical code with the equations of motion of differential rotation of the inner core and mantle where
a large variety of internal configurations can be constructed, i.e., different sub-layers of the mantle. We apply them to different hypothetical interior structure of many previously studied Super-Earths (55 Cnc e, GJ
876d, KOI-55b, GJ 3634b). Numerical exploration of the rotation phase space show that, depending on the
initial conditions and physical parameters like the density of the sub-layers, the effects of the gravitational
coupling on rotation of the outer mantle can be important. For instance, new structures on the spin-orbit
phase space might appear.
B
1
[email protected]
Instituto de Geociências e Ciências Exatas, Unesp - Univ Estadual Paulista
196
Posters
Planetary Systems
PS -1:
#3
Stable low-altitude orbits around Ganymede considering a disturbing body in a
circular orbit
Cardoso dos Santos, J.B1 ; Carvalho, J. P. S.2 ; Vilhena de Moraes, R.2
Ganymede is one of the four Jupiter’s moons which compose the Galilean satellite. It is one of the planetary satellites of greater interest at the present moment among the scientific community. There are some
missions being planned to visit Ganymede and the jovian system. It is possible cite, for example, the Europa
Jupiter System Mission (EJSM). This mission is a cooperation between NASA and ESA in which is planned the
insertion of the spacecraft JGO (Jupiter Ganymede Orbiter) into Ganymede’s orbit. Another mission being
planned for visiting Ganymede is the Jupiter IcyMoon Explorer (JUICE/ESA). Thus, there is a great necessity
for having a better comprehension of the dynamics of the orbits around this planetary satellite. This comprehension is essential for the sucess of this type of mission. In this context, this work aims to perform a search
for low-altitude orbits around Ganymede. An emphasis is given in polar orbits. These orbits can be useful
in the planning of aerospace activities to be conducted around this planetary satellite, with respect to the
stability of orbits of artificial satellites. The study considers orbits of an artificial satellite around Ganymede
under the influence of the third-body perturbation (the gravitational attraction of Jupiter) and the polygenic
perturbations. These last ones occur due to forces such as the non-uniform distribution of mass ( J2 and
J3 ) of the main (central) body. A simplified dynamic model for these perturbations is used. The Lagrange
planetary equations, which compose a system of nonlinear differential equations, are used to describe the
orbital motion of the artificial satellite around Ganymede. The equations showed here are developed using
expansions in eccentricity.
B
1
2
[email protected]
UNESP
UNIFESP
197
Planetary Systems
Posters
PS -1:
#4
Disk-planet interactions
de Paula, L. A.B1 ; Michtchenko, T. A.1
The study of planetary migration is the purpose of the present project. Planet migration is the process by
which a planet’s orbital radius changes in time. The main agent for causing migration is the gravitational
interaction of the young planet with the gaseous disk from which it forms. The already developed models
predict two main types of migration, I and II. The first one is characteristic of low-mass planets which are
embedded in the gaseous disk. The type II is characteristic of the large-mass planets which clear gaps in the
disk around their orbits. Some other kinds of migration are also known and their dynamics will be explored.
The main objectives are (i) the supervised learning of the existing models of planet migration in order to
acquire enough new experience; (ii) application of the models over a variety of physical parameters; (iii)
numerical simulations of migration processes
B
1
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, Universidade de São Paulo.
198
Posters
Planetary Systems
PS -1:
#5
Improvement of TNO’s Ephemerides in the context of stellar occultations
Desmars, J.B1 ; Braga-Ribas, F.1 ; Vieira-Martins, R.1 ; Camargo, J. I. B.1 ; Assafin, M.2
Trans-Neptunian Objects (TNO) and Centaurs are distant and faint solar system objects (around magnitude
20). They are consequently difficult to observe and poorly known objects. Due to their slow motion around
the Sun, their orbits are inaccurate. However, stellar occultations are currently, the only way to precisely
determine some physical characteristics of these objects. Actually, it is possible to determine the size or
the shape with kilometric accuracy, or to highlight binary or multiple objects, or an eventual atmosphere as
tenuous as few nanobars. The prediction of stellar occultations requires both accurate astrometry of stars
and accurate ephemeris.
The current methods of prediction use a constant offset compared to an ephemeris. The ephemeris used
comes from Jet Propulsion Laboratory (JPL) and is determined by fitting the observations or by numerical
integration of the osculating elements. The offset is calculated from the most recent observations as the
mean difference between the observed positions and the ephemeris. This method assumes that the offset
remains constant over a certain period (1 or 2 years).
In this study, we perform a new ephemeris with available observations and observations done for offset
determination. In this context, we have developed a dynamical model of the motion of asteroids (NIMA),
fitted it to observations and determined a new ephemeris and its accuracy.
Comparing the NIMA and JPL ephemerides, we show that the difference between the two ephemerides
is close to the offset at the date of observations but this difference then varies over time, according to a
periodic one-year term (mainly due to the parallax) and a secular term. For some objects, the method of
the offset may however remain accurate when the time between observations and occultation is short or
when the offset’s variations remain small. However, for other TNOs, the difference sharply increases making
inaccurate predictions in the future. Consequently, new ephemerides should be used to make predictions.
Finally, occultations also provide accurate astrometrical positions and therefore new constraints on the
TNO’s motion. We analyze the contribution of previous occultations in the improvement of TNO’S ephemerides
and in prediction of future occultations.
B
1
2
[email protected]
Observatório Nacional/MCTI, Brazil
Observatório do Valongo/UFRJ, Brazil
199
Planetary Systems
Posters
PS -1:
#6
Study of Pluto’s atmosphere from stellar occultation
B1,2
Alex Dias de Oliveira
; B. Sicardy1 ; J. I. B. Camargo2 ; R. Vieira-Martins2 ; M. Assafin3 ; F. Braga-Ribas1,2 ; A. H. Andrei2 ;
D. N. da Silva Neto4 ; A. Doressoundiram1 ; E. Lellouch1 ; F. Roques1 ; T. Widemann1 ; F. Colas5 ; C. Dumas6 ; V. D. Ivanov6 ;
J. H. Girard6 ; J. L. Ortiz7 ; R. Andres8 ; L. Espinoza8 ; L. Vanzi8 ; E. Meza9
With the soon arrival of NASA’s probe New Horizons the demand for physical and dynamic information
about the Pluto system became even greater. As far as ground-based observations are concerned, stellar occultations constitute the only technique capable of providing the temperature and density profiles of Pluto’s
tenuous nitrogen atmosphere. On July 18, 2012, a multi-chord occultation by Pluto was observed from three
stations in Chile: European Southern Observatory ESO/Paranal, San Pedro de Atacama and Santa Martina
(near Santiago). Due to the brightness of the star in the IR (H magnitude= 11.1), the event was recorded with
high signal-to-noise ratio at the ESO 8.2
m Very Large Telescope equipped with the NACO instrument, at
a rate of 5 frames per second, without adaptative optics. This event provides one of the best data set ever
obtained during a Pluto stellar occultation. It allows to build an accurate profile of Pluto’s atmosphere and
reveal local fluctuations possibly caused by gravity waves. Using images taken 20 minutes before the occultations, we can measure the separate fluxes of the star and the Pluto-Charon system. This provides measurement of the residual stellar flux
in the range 0.008
resid
during the occultation. A preliminary analysis shows that
resid
lies
0.018, relative to the full unocculted stellar flux. This flux is related to the temperature
gradient in the lower part of the atmosphere that connects Pluto’s surface (at 35
upper part (at about 105K). Our value of
40K) to the isothermal
resid indicates a temperature gradient in the range 8
for that atmospheric region. Improved values of
resid
15 K · km
1
will be given and constraints to Pluto’s radius will be
presented, as well as temperature profiles derived from inversions of the ingress and egress light curves. This
data will be combine with past information and new data (obtained in 04 May 2013 occultation) to provide
a analysis of Pluto’s atmosphere evolution.
B
1
2
3
4
5
6
7
8
9
[email protected]
LESIA, Observatoire de Paris/Meudon
Observatório Nacional, MCTI
Observatório do Valongo, UFRJ
Centro Universitário Estadual da Zona Oeste
IMCCE, Observatoire de Paris/Meudon
European Southern Observatory
Instituto de Astrofı́sica de Andalucı́a, CSIC
Pontificia Universidad Católica de Chile (PUC)
Facultad de Ciencias, Universidad Nacional de Ingenierı́a, UNI
200
Posters
Planetary Systems
PS -1:
#7
Small asteroid fragments in earth-crossing orbits
Duha, J.B1 ; Afonso, G. B.2
The meteorite that fell in Chelyabinsk, Russia, naturally made many people think it could be a smaller companion of the Asteroid 2012 DA14, which passed close to Earth on that same day. Some asteroid specialists
discarded this hypothesis for two main reasons: The meteorite was too far away from the asteroid, because
the collision happened sixteen hours before the asteroid passed close to Earth. Moreover, it was not traveling,
similarly to asteroid DA14, from south to north. However the possibility of the meteorite being a companion
of the Asteroid 2012 DA14 cannot be completely discarded, due to the followings reasons: The Asteroid 2012
DA14, with a diameter of 45 meters, is very small. It can be considered an asteroid’s fragment, which is usually accompanied by other smaller fragments, scattered in space, practically in the same orbit and possibly
being separated from each other by long distances. Therefore, the meteorite could be a smaller fragment
that was ahead of the larger fragment of the original asteroid. Assuming that 2012 DA14 is not an isolated
asteroid, but the biggest remaining fragment from a previous impact, we developed a model to study the
dynamics of an asteroid fragment, similar to DA14, and its companions, the smaller fragments. This dynamically interesting encounter with planet Earth is addressed by generating the appropriate ephemerides and
impact parameters. The orbital changes that could explain the Chelyabinsk event are discussed. As a result
we find that, there could be a collision of a meteorite before, during, or after the Asteroid 2012 DA14 passing
by, the same way that happens with meteorite showers, which can last several days. Now, because of the meteorite that crashed into Russia, there will be a bigger search for asteroid fragments that pass close to Earth in
the world. Therefore, it would be very interesting to look for them, also, close to the larger fragments, more
easily found.
B
1
2
[email protected]
Federal Institute of Paraná - IFPR
Federal Institute of Amazonas - IFAM
201
Planetary Systems
Posters
PS -1:
#8
Use of Mathematica software in the study of planetary dynamics
Natasha Fioretto AgueroB1 ; Tatiana A. Michtchenko1
This work presents a study on how techniques provided by the algebraic manipulation software Mathematica can be used in the planetary dynamics investigations. The discovery of extra-solar planets orbiting other
stars has been one of the major breakthroughs in astronomy of the past decades, changing our view on the
features of planetary systems, mainly drawn from the observation of the Solar System. Today, over 800 exoplanets are known and the Kepler satellite has recently identified over 3000 additional candidates, most of
them still awaiting for confirmation. We have learned that exoplanets are much more diverse when compared to our own Solar System. Thus, the implementation of advanced manipulation techniques can be of
great importance for the investigation of such unusual configurations of these new worlds. We chose Mathematica, a software that has been increasingly used worldwide due to its great analysis power. The solutions
of transcendent equations (e.g., Kepler’s equation), which cannot be determined through elementary functions, can be analyzed using the functions and the programming techniques employed by this software.
The case that we focus is the 2/1 mean-motion resonance in the two-planet systems. Based on the Mathematica platform, we present animations of the evolution of the stationary solutions configurations as functions of the energy and the angular momentum of the system. The visualization of this evolution is very
important to understand the complicated dynamical proprieties of resonant planetary systems.
B
1
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas (IAG), Universidade de São Paulo (USP)
202
Posters
Planetary Systems
PS -1:
#9
Finding new planets around solar twins using the HARPS/ESO spectrograph
Freitas, C. F.B1 ; Meléndez, J.1
We are using long time series of stellar spectra gathered with the HARPS spectrograph at the La Silla ESO
observatory in order to detect small planets around solar twins through radial velocity variations. There are
instrumental limitations (about 1 m/s) as well as those due to both stellar oscillations and stellar activity. To
get rid of the effects of oscillations, we average several observations within the time scale expected for stellar
oscillations, increasing thus the precision of our radial velocities. We are also studying the stellar activity
of solar twins, because it can induce radial velocity variations that could be confused with the presence of
planets. Finally, we are studying which lines are more sensitive to stellar activity, so that in future studies
we can eliminate them before obtaining the radial velocity for a given observation, allowing thus a better
precision to improve the detection of low-mass planets.
B
1
[email protected]
Universidade de São Paulo
203
Planetary Systems
Posters
PS -1:
#10
Asteroids in the quasi-Hilda comet group
R. Gil-HuttonB1,2
With the aim to identify dormant or extinct comet nuclei among the Hildas, the orbital parameters of more
than 4000 of these asteroids were analyzed to find outliers in the quasi-hilda region. Around 1000 objects
were found in this zone using the orbital excitation parameter and the planes of the Lagrangian elements
as tools to discriminate between Hildas and quasi-hildas objects. Several of these outliers were integrated
backward in time to know their recent dynamical evolution and to better find comet candidates among them.
Preliminary results of this research are shown in this work.
B
1
2
[email protected]
Complejo Astronómico El Leoncito - CONICET
San Juan National University
204
Posters
Planetary Systems
PS -1:
#11
Dust production of the small satellites immersed in the arcs/ring of Saturn
Giuliatti Winter, S. M.B1 ; Sfair, R.1
Images sent by the Cassini spacecraft showed a new structure in the ring system of Saturn, small satellites
immersed in arcs/ring. The satellites Anthe, Methone and Aegaeon are embedded in an arc, while Pallene
shares its orbit with a complete ring. All four satellites are located between the orbits of Mimas and Enceladus. The arcs, composed of small particles, are in corotation resonance with Mimas. These small satellites
can be the source for the arc and the ring particle. In this work we analysed the dust production generated
by collisions of interplanetary objects on the surfaces of the satellites. Satellites smaller than 10km are more
efficient at generating dust particles since they are large enough to present a large cross-section and small
enough to not hold the impact ejecta. For example the satellite Aegaeon, located in the G-ring arc, has a radius smaller than 1km. This satellite could be responsible for the maintenance of the ring, and also the arc,
by generating particles thought collisions with interplanetary objects onto its surface. We used the algorithm
present in Sfair and Giuliatti Winter (2012) to calculated the mass production of these satellites. By assuming
the typical mass flux at Saturn to be 1.8 ⇥ 10
16
kg/ms2 and the nominal parameters of the planet and the
satellite, we could determine the ejecta yield (Y) and the mass production rate (M + ). These values are found
to be Y = 21153.86 and M + = 5.9 ⇥ 10
6
kg/s for the satellite Aegaeon, which produce about 104 kg of dust
particles in a 100years. We also present the mass production of Anthe, Methone and Pallene and discuss the
dynamics evolved in these systems.
B
1
[email protected]
UNESP - Univ. Estadual Paulista
205
Planetary Systems
Posters
PS -1:
#12
Astrometric positions for the irregular satellites of Jupiter, Saturn and Neptune
Gomes Jr, A. R.B1 ; Assafin, M.1 ; Vieira Martins, R.2 ; Camargo, J. I. B.2
The irregular satellites are smaller than the regular ones. They are more distant from the central body and
have more eccentric orbits that may also be retrograde. Explaining their existence is a very important topic
of study in Orbital Dynamics, and gives clues to the formation and evolution of the solar system. However,
their orbits are known with poor precision. Therefore, a more dedicated observational work is necessary. We
have organized and reduced thousands of CCD images from 11 Jovian and Saturnian irregular satellites plus
Nereid. They were observed with the 1.6m and 0.6m telescopes from the OPD (Pico dos Dias Observatory LNA - Itajuba, IAU code 874). More than 4 thousand images were retrieved from a database with about 80
thousand images obtained between 1992 and 2012. In this work, we present the organization and astrometric
reduction of these images. We processed all the 80 thousand images searching the satellites, what means
reduct images from almost 10 CCDs in 3 telescopes using 6 different filters. Many of the older images were
corrupted or had missing coordinates in their FITS headers. A big effort was made to separate and correct
the data. We used the astrometric reduction package PRAIA. The UCAC4 was adopted as the reference frame.
Positive aspects of the OPD data set are the large time span and the great number of observed positions. We
eliminated bad observations to improve the astrometric precision using a sigma-clip procedure. We analyze
the differences between the current ephemeris and the satellites positions for a better understanding of their
orbit status. The projection of the orbits in the plane of the sky, with vectors which represent the position
offsets relative to the ephemeris, was an important analysis tool. It clearly shows the level of contribution
for improving the orbits. A similar work was done by our group with data from the Observatoire HauteProvence. We compared the results from both sets. The OPD positions have 40 mas precision. For some
of the satellites, there are clear improvements to be made to the orbits, mostly in inclination, after a new
integration is made with our new observed positions.
B
1
2
[email protected]
Observatório do Valongo - UFRJ
Observatório Nacional - MCT
206
Posters
Planetary Systems
PS -1:
#13
Shape effects on the spectra of asteroids
Gonzales, J.B1 ; Carvano, J. M.1
Asteroids are irregular solar system bodies, with surfaces composed of grains of different sizes and mineralogical compositions. Their superficial composition can be infered with the aid of semi-empirical models of the bidirectional reflectance, which are commoly used to interpret the integrated reflectance spectra of asteroid that can be observed by Earth-based telescopes. Such interpretation is dificult because the
asteroid spectra are complex nonlinear functions of grain size, mineral abundance and composition. The
two widely-used regolith reflectance models are: the isotropic multiple-scattering approximation (IMSA) of
Hapke (1993), based on the radiative transfer equation and, the one-dimensional geometrical-optics model
for spectral albedo of powdered surfaces, of Shkuratov et al. (1999). These two theories are modeled under
the assumption of a medium stratified and parallel planes . The semiempirical reflectance equation of Hapke
has several free parameters, these are: size of grain, abundance, porosity, rugosity, etc. These model parameters can be obtained by fitting the reflectance measurements, having the optical constants of the mineral
presents on the surface, using as input optical constants derived from laboratory spectra of meteorites and
minerals. The objective of this work is to study the role of the asteroid shape on its observed spectra. For this,
we generate a sythetic spectrum for a nonplanar geometry and, compare it with a spectrum generated with
the same optical parameters as the first but, assuming a planar geometry. The observed differences between
of two spectra are describe in terms of (1) the slope of the spectrum, width and depth of the absorption band,
(2) differenties relatives of abundances and grain size, obtained by a fitting the hapke reflectance equation.
B
1
[email protected]
Observatório Nacional-ON, Rio de Janeiro-Brazil.
207
Planetary Systems
Posters
PS -2:
#14
Identification of families halos in a multi-domain space composed by proper elements
M. E. HuamanB1 ; V. Carruba1 ; R. C. Domingos2 ; D. Nesvorný3 ; F. Roig4 ; D. Souami5,6
If the large families are not limited to what found by hierarchical clustering methods (HCM) in the domain of
proper elements (a,e,sin(i)), that seems to be biased to find compact, relatively young clusters, but that there
exists an extended population of objects with similar taxonomies and geometric albedo, that can extend to
much larger regions in proper elements and frequencies domains: the family ”halo”.
Numerical simulations can be used to determining a good estimate of the possible orbital extension of
a family ”halo” and provide estimates of the age of the family that can then be compared with ages of the
family obtained with other methods. Other autors have identified families halos by: i) an analysis in proper
elements domains, ii) or by using SDSS-MOC4 multi-band photometry to infer the asteroid taxonomy, iii) or
by a combination of the two methods.
The limited number of asteroids for which geometric albedo was known, were restricted in the past the
extensive use of this additional parameter, which is however of great importance in identifying an asteroid
taxonomy. But now a new availability of geometric albedo data from the WISE mission for about 100,000
asteroids significantly increased the sample of objects for which such information, with some errors, is now
known.
In this work we proposed a new method to identify families halos in a multi-domain space composed by
proper elements, SDSS- MOC4 (a’,i-z) colors, and WISE geometric albedo for the whole main belt . Assuming
that most families were created by the breakup of an undifferentiated parent body, they are expected to be
homogeneous in colors and albedo. The new method is quite effective in determining objects belonging
to a family halo, with low percentages of likely interlopers, and results that are quite consistent in term of
taxonomy and geometric albedo of the halo members.
B
1
2
3
4
5
6
[email protected]
Unesp, Univ. Estadual Paulista, Grupo de Dinâmica Orbital e Planetologia, Guaratingueta, Brazil
INPE, Instituto Nacional de Pesquisas Espaciais, São José dos Campos, Brazil
SWRI, SouthWest Research Institute, USA
ON, Observatório Nacional, Brazil
UPMC, Université Pierre et Marie Curie, France
SYRTE, Observatoire de Paris, Systèmes de Référence, Temps Espace, France
208
Posters
Planetary Systems
PS -2:
#15
A New Paradigm for Habitability in Planetary Systems: the Extremophile Zone
Janot-Pacheco, E.B1 ; Bernardes, L.1
About a thousand exoplanets habe been discovered so far. Planetary surface temperature may strongly
depend on its albedo and geodynamic conditions. We have fed exoplanetary data from the Encyclopedia
database (Schneider, 2013) with a comprehensive model of Earth’s atmosphere and plate tectonics. As the
main greenhouse effect is CO2, its partial pressure has been taken as a free parameter to calculate the surface
temperature of some known planets. We also investigated the possible presence of ”exomoons“ belonging
to giant planets capable of harbour dynamic stability and to retain atmospheric layers and keep geodynamic
activity for long time spans. Collected information on biological data of earthly micro-organisms classified
as “extremophiles” indicate that such kind of microbial species could dwell on the surface of many exoplanets and exomoons. We thus propose an extension of the mainly astronomically defined “Habitable Zone”
concept into the more astrobiologically “Extremophile Zone”, taking into account other refined parameters
allowing survival of more robust life forms. This contribution comes from an ongoing project developed by
a French-Brazilian colaboration in Astrophysics and Biophysics to search for living fingerprints in astrobiologically interesting exoplanets.
B
1
[email protected]
IAG-USP
209
Planetary Systems
Posters
PS -2:
#16
Close-in planets around giant stars
Jones, M. I.B1 ; Jenkins, J. S.1 ; Rojo P.1 ; Melo, C. H. F.2
In 2009 we started a RV survey aimed at studying the population of planets in close-in orbits around giant
stars. So far, we have collected multi-epochs spectra for a sample of 166 bright targets in the southern hemisphere, resulting in the discovery of several planets and binary systems. Additionally, many other substellar
candidates in long-period orbits have emerged, which still have to be confirmed. In this talk I will present
the goal of our project, the observing strategy and the reduction analysis. Finally I will present our results
and I will discuss about the possible explanation for the lack of close-in planets orbiting post-MS stars.
B
1
2
[email protected]
Universidad de Chile
ESO
210
Posters
Planetary Systems
PS -2:
#18
Dynamical evolution of differentiated asteroid families
Martins-Filho, W. S.B1 ; Carvano, J. M.1 ; Mothe-Diniz, T.2 ; Roig, F.1
The project aims to study the dynamical evolution of a family of asteroids formed from a fully differentiated
parent body, considering family members with different physical properties consistent with what is expected
from the break up of a body formed by a metallic nucleus surrounded by a rocky mantle.
Initially, we study the effects of variations in density, bond albedo, and thermal inertia in the semi-major
axis drift caused by the Yarkovsky Effect. The Yarkovsky Effect is a non-conservative force caused by the
thermal re-radiation of the solar radiation by an irregular body. In Solar System bodies, it is known to cause
changes in the orbital motions (Peterson, 1976), eventually bringing asteroids into transport routes to nearEarth space, such as some mean motion resonances. We expressed the equations of variation of the semimajor axis directly in terms of physical properties (such as the mean motion, frequency of rotation, conductivity, thermal parameter, specific heat, obliquity and bond albedo). This development was based on the
original formalism for the Yarkovsky Effect (i. e., Bottke et al., 2006 and references therein). The derivation of
above equations allowed us to closely study the variation of the semi-major axis individually for each physical parameter, clearly showing that the changes in semi-major axis for silicate bodies is twice or three times
greater than for metal bodies.
The next step was to calculate the orbital elements of a synthetic family after the break-up. That was accomplished assuming that the catastrophic disruption energy is given by the formalism described by Stewart
and Leinhardt (2009) and assuming an isotropic distribution of velocities for the fragments of the nucleus
and the mantle. Finally, the orbital evolution of the fragments is implemented using a simpletic integrator,
and the result compared with the distribution of real asteroid families.
B
1
2
[email protected]
Observatório Nacional, ON/MCT, Rio de Janeiro, RJ, Brasil
Observatório do Valongo, UFRJ, Rio de Janeiro, RJ. Brasil
211
Planetary Systems
Posters
PS -2:
#19
The Evolution of the G Ring Arc under the Effects of the Resonance with Mimas and the
Solar Radiation Force
Mourão, D. C.B1 ; Giuliatti Winter, S. M.1 ; Sfair, R.1
The small satellite Aegaeon, less than 1km across, is embedded in an arc located in the G ring of Saturn.
This satellite belong to a new class of structures imaged by the Cassini spacecraft, which is formed by small
satellites immersed in arcs. Aegaeon is also locked in a 7:6 corotation resonance with the satellite Mimas.
It has been proposed that Aegaoen, along with a set of large particles located in this arc, is responsible for
the maintenaince of the G ring against dissipative forces. In this work, we study the orbital evolution of a
sample of tiny particles (sizes ranging from 1 to 10µm) under the gravitational effects of Mimas and the solar
radiation pressure. These particles were initially located in the arc about ±20km from the semimajor axis
resonance of Aegaeon with ±30 in longitude. Our results show that, despite the particles are initially in a
corotation resonance with Mimas, the effects of the solar radiation pressure remove the particles from the
arc in a timespan of 50yrs. These particles stay confined in the G ring.
B
1
[email protected]
UNESP - Univ Estadual Paulista
212
Posters
Planetary Systems
PS -2:
#20
Programa de observación de ocultaciones de estrellas desde el Observatorio Nacional
de Llano del Hato
O. NaranjoB1 ; G. Navas2 ; P. Rosenzweig1 ; E. Guzmán1 ; R. Alvarez1 ; L. Zerpa1,2 ; J. Villarreal1,2 ; N. Villa
La observación de ocultaciones de estrellas por objetos del Sistema Solar permite el estudio de la posible
atmosfera presente en el objeto que oculta a la estrella, su forma, tamaño y verificar la existencia de posibles
satélites asociados al mismo. Recientemente, hemos comenzado la observación de ocultaciones de estrellas
por objetos del Sistema Solar, usando los telescopios Reflector f/5; f/21 de 1-m y el telecopio Refractor de
0.65-m del Observatorio Nacional de Llano del Hato, Mérida. En ambos telescopios se ha acoplado una
cámara CCD en su foco. Hasta el presente se ha observado ocultaciones de estrellas por planetas menores,
objetos cercanos a la Tierra, cometas y el satélite Titan de Saturno. Algunas de estas ocultaciones observadas
no coinciden con las predicciones de su trayectoria. En este trabajo se presentan algunos resultados de estas
observaciones.
B
1
2
[email protected]
Universidad de los Andes, Facultad de Ciencias, Departamento de Fı́sica, Grupo de Astrofı́sica Teórica. Mérida-Venezuela
Centro de Investigaciones de Astronomı́a (CIDA)
213
Planetary Systems
Posters
PS -2:
#21
Observación de objetos cercanos a la Tierra (Observation of Neos)
O. Naranjo1 ; G. NavasB2 ; P. Rosenzweig1 ; E. Guzmán1 ; L. Zerpa1,2 ; R. Alvarez1 ; J. Villarreal1,2 ; D. Collazo1
El estudio de objetos cercanos a la Tierra es importante por cuanto permite conocer sobre las propiedades
fı́sicas de estos objetos, su origen y las condiciones existentes en el sistema solar durante su formación.
Además, por la ubicación única de nuestro observatorio cercano al ecuador terrestre, nos permite el monitoreo de objetos moviéndose norte y sur y viceversa. Estas observaciones fueron realizadas usando el telescopio Reflector f/5; f/21 de 1-m del Observatorio Nacional de Llano del Hato, junto con el sistema de filtros
BVRI. La astrometrı́a y fotometrı́a realizada sobre cada objeto nos permitió determinar su posición en la
órbita, su color y curva de luz. Se presentan resultados obtenidos de la observación de varios objetos cercanos a la Tierra.
Palabras Claves: Objetos cercanos a la Tierra, planetas menores, atmósferas, astrometrı́a, fotometrı́a
B
1
2
[email protected]
Universidad de los Andes, Facultad de Ciencias, Departamento de Fı́sica, Grupo de Astrofı́sica Teórica. Mérida-Venezuela
Centro de Investigaciones de Astronomı́a (CIDA)
214
Posters
Planetary Systems
PS -2:
#22
The Behavior of Regular Satellites during the Nice Model’s Planetary Close Encounters
Nogueira, E. C.B1,2 ; Gomes, R. S.2 ; Brasser, R.3
The behavior of the regular satellites of the giant planets during the instability phase of the Nice model needs
to be better understood. In order to explain this behavior, we used numerical simulations to investigate the
evolution of the regular satellite systems of the ice giants when these two planets experienced encounters
with the gas giants. For the initial conditions we placed an ice planet in between Jupiter and Saturn, according to the evolution of Nice model simulations in a ‘jumping Jupiter’ scenario (Brasser et al. 2009). We
used the MERCURY integrator (Chambers 1999) and cloned simulations by slightly modifying the Hybrid
integrator changeover parameter. We obtained 101 successful runs which kept all planets, of which 24 were
jumping Jupiter cases. Subsequently we performed additional numerical integrations in which the ice giant
that encountered a gas giant was started on the same orbit but with its regular satellites included. This is
done as follows: For each of the 101 basic runs, we save the orbital elements of all objects in the integration
at all close encounter events. Then we performed a backward integration to start the system 100 years before
the encounter and re-enacted the forward integration with the regular satellites around the ice giant. These
integrations ran for 1000 years. The final orbital elements of the satellites with respect to the ice planet were
used to restart the integration for the next planetary encounter (if any). If we assume that Uranus is the ice
planet that had encounters with a gas giant, we considered the satellites Miranda, Ariel, Umbriel, Titania and
Oberon with their present orbits around the planet. For Neptune we introduced Triton with an orbit with a
15% larger than the actual semi-major axis to account for the tidal decay from the LHB to present time. We
also assume that Triton was captured through binary disruption (Agnor and Hamilton 2006, Nogueira et al.
2011) and its orbit was circularized by tides during the ⇠500 million years before the LHB.
B
1
2
3
[email protected]
Universidade Federal Fluminense, Brasil
Observatório Nacional, Brasil
Institute for Astronomy and Astrophysics, Academia Sinica, Taiwan
215
Planetary Systems
Posters
PS -2:
#23
Small-body colors from the UV to the IR: bringing together all space and ground-based
observations
Penteado, P.B1 ; Trilling, D.1
The main current asteroid taxonomical systems are defined from ground-based observations, limited to
3100-10600 Å (Tholen, Zellner et al. (1985)), and 4400-9200 Å (SMASS, Bus and Binzel (2002))). This narrow wavelength range does not include several regions useful to determine asteroid properties, such as: 1)
the well-known spectral features in the near-IR (20000-50000 Å) that differentiate between common asteroid
and meteorite minerals and indicate the presence of water, methane or other volatiles; 2) the far IR, which
probes the bodies’ emission, thermal inertia and albedo; 3) the UV, where the degree of darkening probes
the surface grain properties and space weathering. The few existing studies using multiple instruments from
the UV to the IR (ground, Earth-orbit and flyby observations) have been limited to targeted observations of
special-interest bodies (Perna et al., 2013, Kueppers et al. 2013, Müller et al. 2012, to name just the most
recent). We aim to obtain UV to IR colors of a large sample of bodies, to study how they are distributed and
how these colors differentiate among bodies with similar spectra on the standard taxonomies. The data are
being gathered from archives of multiple space- and ground-based instruments: GALEX, HST, SDSS, 2MASS,
Spitzer, WISE and Herschell. Such a combined use of multiple archived observations is commonly done for
fixed (non-Solar System) astronomical targets, which can be easily found by their RA and Dec. To obtain
such data for Solar System bodies, we built a database to index all archive observations of each known body.
We used their orbits, integrated into the past, to build an index in the Time/RA/Dec domain, where we locate each archive footprint to determine if it contains a known Solar System body. We present a preliminary
cluster analysis, using a small sample of objects identified in multiple instruments, as well as the magnitude
distributions on different colors, for a larger sample of objects, which were not matched among the different
instruments. In the future we will expand the database to include more observations (more instruments and
more bodies), and the populations we identify will be compared to spacecraft UV to IR spectra of those few
bodies observed in close passes and with high resolution spectra.
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1
[email protected]
Department of Physics and Astronomy, Northern Arizona University
216
Posters
Planetary Systems
PS -2:
#24
The most common habitable planets – atmospheric characterization of the subgroup
of fast rotators
Pinotti, R.B1
The current search for habitable planets has focused on Earth-like conditions of mass, volatile content and
orbit. However, rocky planets following eccentric orbits, and drier than the Earth, may be a more common phenomenon in the Universe. For the subgroup of fast rotators, it is suggested that their atmospheric
thermal capacitance, subject to the radiative forcing of their parent stars, may provide researchers in the
near future with a simple method for the determination of a robust lower limit of atmospheric thickness.
This technique, together with the spectroscopic analysis of resolved planets from their stars, both allowed
by planned spaceand ground-based observatories with thermal infrared capabilities, would enable us with
a better understanding of the habitability of this class of planets. The technique works better for shorter
orbital periods, but since the tidal-lock radius ofMdwarfs encompasses their Habitable Zone (HZ), the optimum targets would be planets around K dwarf stars. The atmospheric thermal capacitance could also
expand the range of HZs for shorter orbits, particularly for planets around M dwarf stars, since the higher
frequency of the periodic radiative forcing dampens the surface temperature variation considerably.
B
1
[email protected]
Observatório do Valongo, Universidade Federal do Rio de Janeiro, UFRJ
217
Planetary Systems
Posters
PS -2:
#25
Asteroids Atiras: study of stability and dynamical analysis of the region
Ribeiro, A. O.B1 ; De Prá, M. N.1 ; Roig, F.1 ; Carvano, J. M.1
The Near Earth Asteroids (NEAs) are a dynamic group of asteroids with perihelium q < 1.333 UA. Dynamical studies show that the NEAs are an unstable population, and that the Main-Belt is the main source for
replenishing asteroids in that region. The NEAs are divided in four subgroups: Amor, Apollo, Aten e Atira. In
the literature, objects with aphelium Q < 0.983 UA are usually called Atiras, Inner Earth Object (IEO), and
sometimes Apohele. Being extremely difficult to observe due to it’s proximity to the Sun, only 12 Atiras are
presently known, while dynamical arguments and extrapolation from the known polulation suggests an expected population of around 375 asteroids in this region. An important aspect of the objects in this region is
the threat they may represent, since several dynamic mechanism (as, for example captures by secular resonances and/or close encounters with Venus and Mercury) may reinject these objects em Earth crosser orbits.
This work proposes a dynamical study of the region of Atiras asteroids. A grid with 2500 test particles with
semi-mayor axis between 0.2UA and 0.38 UA; eccentricity between 0 and 0.8, were equidistantly distributed.
All particles have orbital inclination of 0.05o and the remaining orbital elements were fixed with the mean
value of the observed Atiras asteroids. For each point in the grid, the orbit diffusion coefficient is calculated
and a map of the diffusion in the region is made. The results show a region of stability between 0.2 UA and
0.3 UA in semi-mayor axis for eccentricity until 0.4. It is possible to identify the 9:7 resonance with Mercury,
this temporarily stabilizes the objects a increase the eccentricity. This region of stability found can help to
design more target surveys and improve the odds of detecting new Atiras
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1
[email protected]
Observatório Nacional, Rua General José Cristino 77, Rio de Janeiro, 20921-400, Brazil
218
Posters
Planetary Systems
PS -2:
#26
Spin-Orbit Resonances in Super-Earth Systems Close to Mean-motion
Commensurabilities
Ribeiro, F. B.B1 ; Callegari Jr., N.2
There is a great deal of planets in close-in orbits and low mass on order of magnitude less than 10 Earth
mass. Valencia et al. (2006) call them by Super-Earths. Recently, several efforts have been done in order to
understand the dynamical of rotation of these planets, including spin-orbit resonance and spin tidal evolution. In the referred papers, it is considered a single planet whose motion around the star is governed by the
rules of the two-body problem. However, many Super-Earths are present in system where other terrestrial
or giant planets are present, and that problem must be checked. In this work we study the dynamical effects
of mean-motion commensurabilities on rigid body rotation and spin-orbit resonances. Emphasis is given in
the cases of the multi-planetary systems Kepler-11, KOI-55 and KOI-961, where the mean motions of several
pairs of planets are commensurable. In some cases we have observed that the period associated to a particular commensurability is close to the period of the free libration of the rotation of one of the super-Earths.
Thus, we investigate the role of the mean motion resonance on the synchronous rotation. Depending on the
initial conditions inside the synchronous domain, the stable librations induced by the torque of the central
star on the figure of the planet can lead to instabilities on its rotation which is not expected in such regular regions of rotational phase space. This phenomenon has been observed in the cases of Kepler-11 b (disturbed
by Kepler-11 c), KOI-55 b (disturbed by KOI-55 c), KOI-961c (disturbed by KOI-961b and KOI-961d).
B
1
2
[email protected]
UNESP, Physics Department, Rio Claro, SP, Brazil
UNESP, Demac, Rio Claro, SP, Brazil
219
Planetary Systems
Posters
PS -3:
#27
V-type asteroids among the Mars crosser population
1
B1
Ribeiro, A. O. ; Roig, F.
; Cañada-Assandri, M.2,3 ; Carvano, J. M.1 ; Jasmin, F. L.1 ; Alvarez-Candal, A.1,4 ; Gil-Hutton, R.2,3
We search for asteroids belonging to the V taxonomic class which have not been detected up to now among
the populations of Mars crossing asteroids. This is motivated by the fact that the Mars crossing regime is
a path to deliver asteroids from the Inner Main Belt to the Earth crossing space, and both the Inner Main
Belt and the population of Earth crossing asteroids contains a significant fraction of V-type bodies. We selected 18 candidate V-type asteroids in the Mars crossing region using observations contained in the Sloan
Digital Sky Survey Moving Objects Catalog. Then, we observed 4 of these candidates to take their visible
reflectance spectra using the Southern Astrophysical Research Telescope (SOAR). We also performed the numerical simulation of the orbital evolution of the observed asteroids. We confirmed that 3 of the observed
asteroids belong to the V class, and one of them follows a path that drives it to an Earth collision in a few tens
of million years.
B
1
2
3
4
[email protected]
Observatório Nacional, Rio de Janeiro, Brazil
Universidad Nacional de San Juan, San Juan, Argentina
Complejo Astronómico El Leoncito - CONICET, San Juan, Argentina
Instituto de Astrofı́sica de Andalucı́a - CSIC, Granada, Spain
220
Posters
Planetary Systems
PS -3:
#28
Photometry and Spectroscopy of Asteroids Rich in Volatils of the Type Main Belt
Comets (MBC)
Rondón, E.B1 ; Carvano, J. M.1 ; Lorenz-Martins, S.2
Nine asteroids of the main belt have shown cometary activity. These objects have been called Main Belt
Comets (MBC). The physical source of their activity can be diverse; among the possible causes are collision
and sublimation. In this work we use a dust distribution model associated with the asteroid coma to study
the photometric and spectroscopic properties of these objects, from which we can estimate the parameters
associated with position of the particle in the coma, the size of the grain and with the velocity distribution,
and thus simulating a collision in the asteroids. We study the influence of grain size on the spectrum of
asteroids, using the Hapke model for the sun light reflected at the surface asteroids and attenuated by the
coma, and using the monte carlo method for the sun light scattered by the coma into the line of sight of
the observer, following the approach of Carvano & Lorenz (2010) which modeled the effects of a faint dust
coma on the asteroid (5201) Ferraz-Mello spectra and other objects. This model was capable to produce
an increase in the reflectance in the shorter wavelength, and they show that the presence of a faint coma
produces unusual reflectance. In our model, we study other distribution for the grains and we added the
effect of the solar phase angle on the spectra.
B
1
2
[email protected]
Observatório Nacional (COAA), Rua Gal. José Cristino 77, São Cristóvão, CEP 20921-400 Rio de Janeiro RJ, Brazil
Universidade Federal do Rio de Janeiro/Observatório do Valongo. Ladeira do Pedro Antônio, 43 - 20080-090 Rio de Janeiro, Brazil
221
Planetary Systems
Posters
PS -3:
#29
The IMPACTON project: rotational properties of NEAs
B1
Silva J. S.
; Lazzaro D.1 ; Rodrigues T.1 ; Carvano J. M. F.1 ; Roig F.1 ; Dos Santos E.1 ; Jasmin F. L.1 ; Gonzales J.1 ; Ribeiro
A. O.1 ; Hasselmann P. H1 ; Nascimento M.1
The main scientific goal of the IMPACTON project is to characterize the physical properties, of the largest
possible number of NEOs discovered by other search projects (Lazzaro et al. 2012). In the present paper
we will report about the rotational properties of a set of NEAs. The observations were carried on at the 1m telescope of the Observatório Astronômico do Sertão de Itaparica (OASI, MPC code Y28), located in the
North-eastern part of Brazil. The photometric observations were obtained between March and June, 2012,
using a 1024 x 1024 pixels CCD, with a 13 x 13 micron size, and the R filter (Johnson). Among the observed
NEAs we computed the rotational period for (85818) 1998 XM4, , (312473) 2008 SX245, (330825) 2008 XE3,
being 5.8, 3.4 and 4.0 hours, respectively. For other objects only strong indications on the rotational period
were obtained, among these are: (154007) 2002 BY, (112221) 2002 KH4, (326732) 2003 HB6, 2006 VY13, 2011
YV15.
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1
[email protected]
Observatório Nacional
222
Posters
Planetary Systems
PS -3:
#30
Connecting the Circumstellar Habitable Zone to the Galactic Habitable Zone
Sime, M. K.B1 ; Friaça, A. C. S.1
The circumstellar habitable zone (CHZ) is the region around a star where a planet can exhibit liquid water
on its surface, which is essential for the life as we know it. The outer boundary of the CHZ is sensitive to
the amount of greenhouse effect. The main greenhouse gases are water vapor, carbon dioxide and methane.
Therefore, if there is a larger availability of carbon, the greenhouse effect due to carbon dioxide as methane
increases. In the present work we explore the carbon connection which links galactic evolution models and
the extension of the CHZ. The galactic habitable zone (GHZ) is the region of the Galaxy within which the
probability of life arises and survives is higher. The boundaries of the GHZ are determined by the survival
probability against catastrophic events (Sne, GRBs), the probability of the formation of Earth-like planets
and long timescales for Darwinian Evolution. We perform calculations of the GHZ using a chemical evolution model for the Galaxy. A novelty of the present work is that we focus on the evolution of carbon to derive
a constraint between biomass (heavily dependent on the carbon abundance) and the extension of the CHZ,
reflection the amount of greenhouse effect, which, in turn, is dependent on the carbon abundance.
B
1
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, Universidade de São Paulo
223
Planetary Systems
Posters
PS -3:
#31
Stellar occultations by trans-Neptunian objects
Vieira-Martins, R.B1 ; Braga-Ribas, F.1 ; Camargo, J. I. B.1 ; Assafin, M.2 ; Sicardy B.3
The discovery of the trans-Neptunian objects (TNOs) since 1992 led to the development of new models about
the giant planets’ initial evolution, giving rise to new insights on the formation of the solar system. The consolidation of these models depends on a more detailed knowledge of the physical properties of TNOs such as
mass, density, shape, albedo and atmosphere’s detection. The goal of our work concerns the determination
of these parameters for a significant number of objects. As their distances do not allow a good determination
of their physical parameters, we use the technique of stellar occultations. It consists of observing the star’s
light variation when an object passes between the star and the observer. This technique allows obtaining
the TNOs’ sizes with accuracies of few kilometers which combined with other data provides the physical
parameters above. Almost 10 years ago we associated to a large international collaboration that develops a
important effort in order to observe stellar occultations by outer solar system objects. Today this collaboration is being led by three groups based in Paris, Granada and Rio. They perform the predictions of short and
long-term occultations, the organization of observational campaigns, the reductions and analysis of data.
In particular, the Rio Group has developed a process for long-term predictions (up to 2015) for 50 TNOs,
which involved the construction of a catalog of 20 million stars down to 20th magnitude with positions that
have astrometric precisions better than 50 mas. This catalog was obtained from observations made with
the wide-field camera (WFI) of the 2.2-meter telescope at La Silla/ESO. In order to refine de previsions our
group started in the Brazilian Laboratório Nacional de Astrofı́sica a systematic program of astrometric observations of stars and objects involved in some future occultations. We constructed a web page to inform
the observers, which is updated several times a week with the refinements of the predictions, and we are
organizing in Brazil an observer network involving professional and amateur astronomers. We have also actively worked in the reductions and analysis of the light curves resulting from occultations. All this work has
given rise to several articles in journals with our participation. At this meeting we will present an overview
on the main results achieved in our occultations’ works. Details of these results will be presented in other
communications in this meeting.
B
1
2
3
[email protected]
Observatório Nacional
Observatório do Valongo/UFRJ
Observatoire de Paris/Meudon
224
Posters
Planetary Systems
PS -3:
#32
Morphological analysis of the tail structures of comet 1P/Halley 1910 II
Voelzke, M. R.B1 ; Izaguirre, L. S.2
Eight hundred and eighty six images from September 1909 to May 1911 are analysed for the purpose of identifying, measuring and correlating the morphological structures along the plasma tail of 1P/Halley. These
images are from the Atlas of Comet Halley 1910 II (Donn et al., 1986). A systematic visual analysis revealed
304 wavy structures along the main tail and 164 along the secondary tails, 41 solitary waves (solitons), 13
Swan-like tails, 26 disconnection events (DEs), 166 knots (regions of higher density of matter) and six shells.
While the wavy structures denote undulations or a train of waves, the solitons refer to the formations usually
denominated kinks. In general, it is possible to associate the occurrence of a DE and/or a Swan-Tail with
the occurrence of a knot, but the last one may occur independently. It is also possible to say that the solitons occur in association with the wavy structures, but the reverse is not true. The 26 DEs documented in
26 different images allowed the derivation of two onsets of DEs, i.e., the time when the comet supposedly
crossed a frontier between magnetic sectors of the solar wind (Brandt and Snow, 2000). Both onsets of DEs
were determined after the perihelion passage with an average of the corrected velocities Vc equal to (57 ± 15)
km s
1
. The mean value of the corrected wavelength c measured in 70 different wavy structures is equal to
(1.7 ± 0.1) ⇥ 106 km and the mean amplitude A of the wave (measured in the same 70 wavy structures cited
above) is equal to (1.4 ± 0.1) ⇥ 105 km. The mean value of the corrected cometocentric phase velocity Vpc
measured in 20 different wavy structures is equal to (168 ± 28) km s
1
. The average value of the corrected
velocities Vkc of the knots measured in 36 different images is equal to (128 ± 12) km s
1
. There is a tendency
for A and c to increase with increasing cometocentric distance. The results of this work agree with the earlier research from Voelzke and Matsuura (1998), which analysed comet P/Halley’s tail structures in its last
apparition in 1986.
B
1
[email protected]
Cruzeiro do Sul University
225
Planetary Systems
Posters
PS -3:
#33
Contributions of geomorphology for the understanding of landscape evolution in
rocky planets of the Solar System
Alexandre, S. T.B1 ; Nunes, N. A.1 ; Guerra, A. J. T.1
The combination of endogenous, exogenous and dynamic processes is responsible for the way landforms are
shaped on Earth. The application of geomorphology, a branch of science dedicated to understanding the
land-surface in connection with the processes that created it, with sophisticated planetary imaging technologies, is improving our knowledge on the formation and evolution of surface features in different contexts. Using Mars as model-object, this study aims to apply the knowledge of geomorphology and related
sciences for understanding the processes and evolution of the Martian relief. Using mapping techniques of
Jmars and Jearth, we attempt to draw connections between morphostructure and morphology of an area on
Mars, Candor Chasma, and an area on Earth related to the feature of canyons. The comparison of the two
bodies can provide valuable clues on similarities and differences on the evolution of these planets.
B
1
[email protected]
Laboratory of Environmental Geomorphology and Soils Degradation, Federal University of Rio de Janeiro.
226
Posters
Planetary Systems
PS -3:
#34
Finding ’jumps’ in light curves using change-point algorithms
Boufleur, R. C.B1 ; Emilio, M.2 ; de la Reza, J. R.1 ; Janot-Pacheco, E.3
In the search for extra solar planets using the transit method, astronomers are concerned in to obtain the
maximum information of the photons received from the stars. Such transits produce characteristic effects
in the light curves which allow to determine some physical parameters of the planet candidate. The incidence of high-energy particles and the consequent hot pixels generation, or even thermal variations of the
instrument, cause sudden changes in the light curves at short time intervals. Thereby an algorithm for the
identification and treatment of such phenomena in data is as important as a good transit search due to bias
introduced. A set of techniques known as change-point are commonly employed in various fields of knowledge to detect abrupt variations in observations at short intervals of time. In an extensive comparison Reeves
et al. (2007) shows that there is not an unique improved algorithm which covers all the cases. The decision
on which to use depends on various characteristics of the time series analyzed, including the range and the
occurrence frequency of these breaks in the series. On the other hand, Jann (2000) studied the occurrence of
multiple change-point time series. We develop in this work a methodology using change-point algorithms
dedicated to the detection and location of jumps in the light curves. The statistics we used to do the calculations involved the standard homogeneity test. We show that our preliminary results are satisfactory and
as events of abrupt change does not appear periodically opposed to transit ones they meet with the future
objectives of the project that aims at the same time to detects the change-points and transits based on the
probability density results.
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1
2
3
[email protected]
ON - MCTI. Rio de Janeiro, Brasil
UEPG. Ponta Grossa / PR. Brasil
IAG/USP. São Paulo. Brasil
227
Planetary Systems
Posters
PS -3:
#35
Towards understanding the late evolution of protoplanetary disks
Caceres, C.B1
Understanding the evolution of circumstellar disks around young stellar objects is crucial for theories of
star and planet formation. Most young stellar objects are either accreting classical T Tauri stars with “full”
disks or non-accreting weak-line T Tauri stars (WTTSs) with bare stellar photospheres, which suggests that
the transition phase between the two states must be very short. Currently, the only mechanism able to
consistently explain the rapidly vanishing disks is photoevaporation. However, the photoevaporation rates
predicted by current models differ by several orders of magnitude which makes modelling of protoplanetary
disk evolution a rather difficult exercise. We use ALMA cycle 0 observations of a large sample of WTTS in
Lupus to conclusively distinguish primordial photoevaporating disks from young debris disks. We derive
mass limits for all the disks in our sample which puts tight constraints on current photoevaporation models.
B
1
[email protected]
Universidad de Valparaiso
228
Posters
Planetary Systems
PS -3:
#36
Finding minor Bodies with the JPAS/J-PLUS photometric surveys
De Prá, M. N.B1 ; Carvano J. M. F.1 ; Lazzaro D.1 ; Roig F.1 ; Mothé-Diniz T.2 ; Alvarez-Candal, A.1 ; J-PAS Team
The JPAS/J-PLUS is a joint Spanish-Brazilian project that aims to map an area of the sky of 8000 square
degrees, in order to measure, with unprecedented accuracy, the redshifts of a large sample of extragalactic
objects up magnitude 23. It involves the installation of two telescopes on the Javalambre Mountains, in
Spain. The T250 telescope will have an aperture of 250cm and will be equipped with a camera with a 3
square degree field of view and will use a set of 56 filters (54 narrow band + 2 wide band) covering the 0.31.0 micron range, while the T80 telescope (presently on commissioning phase) will have a camera with 2
square degree field of view and will use a set of 12 narrow and intermediate band filters covering the same
wavelength range. During its execution, the surveys will also observe a large number of minor Solar System
bodies. Here we will discuss the expected efficiency of the J-PLUS survey in finding minor bodies.
B
1
2
[email protected]
Observatório Nacional
Observatório do Valongo
229
Planetary Systems
Posters
PS -3:
#37
Transit Timing Variations analysis in exoplanet host stars
B1
Petrucci, R.
; Jofre, E.2 ; Schwartz, M.1 ; Cúneo, V.1 ; Martı́nez, C.2 ; Saker, L.2 ; Ferrero, L.2 ; Artur, E.2 ; Gómez, M.2 ;
Mauas, P.1
In June of 2011 we started a continuous photometric monitoring of transiting planets host stars in the southern hemisphere, with the aim of searching for periodic variations in their mid-transit times. Such variations
(or TTVs) are produced by the gravitational action of other bodies in the system that disturb the semimajor
axis and therefore the orbital period of the transiting planet. The smaller the mass of the disturber the lower
the amplitude of the variation and therefore high precision (tens of seconds) is required to measure the central transit times. In this paper, we present a full analysis of TTVs of one of the objects with transits observed
from 2011 to the present.
B
1
2
[email protected]
Instituto de Astronomı́a y Fı́sica del Espacio, Argentina
Observatorio Astronómico de Córdoba, Argentina
230
Posters
Planetary Systems
PS -3:
#38
About Hohmann Transfer with Orbital Plane Change
Ángel RincónB1 ; Patricio Rojo1
We analitically studied the generalized Hohmann orbital transfer by considering non coplanar and elliptical orbits instead of planar and circular. It was done in order to find the transfer orbit that minimizes the
energy and therefore missing mas of a satellite through the application of two non-tangetial impulses. We
found an analytical expression that leads to minimize the fuel cost after assuming some reasonable physical
constraints. Finally, we discuss some possible configurations and applications to our model.
B
1
[email protected]
Astronomy department, Universidad de Chile
231
Planetary Systems
Posters
PS -3:
#39
Palaeogeographic reconstruction of Minchin palaeolake system, South America: the
influence of astronomical forcing
Andrea Sánchez-Saldı́asB1 ; Richard A. Fariña2
Current palaeoclimatic reconstructions for the Rı́o de la Plata region during the latest Pleistocene (30,000
to 10,000 years BP) propose dry conditions, with rainfall at the Last Glacial Maximum amounting to onethird of today’s precipitation. Despite the consequential low primary productivity inferred, an impressive
megafauna existed in the area at that time. Here we explore the influence of the flooding from a huge extinct
system of water bodies in the Andean Altiplano as a likely source for wet regimes that might have increased
the primary productivity and, hence, the vast number of megaherbivores. The system was reconstructed
using specifically combined software resources, including Insola, Global Mapper v13, Surfer and Matlab.
Changes in water volume and area covered were related to climatic change, assessed through a model of
astronomical forcing that describes the changes in insolation at the top of the atmosphere in the last 50,000
years BP. The model was validated by comparing its results with several proxies (CH4, CO2, D, 18O) from
dated cores taken from the ice covering Antarctic lakes Vostok and EPICA Dome C. It is concluded that the
Altiplano lake system drained towards the southeast in the rainy seasons and that it must have been a major
source of water for the Paraná-Plata basin, consequently enhancing primary productivity within it.
B
1
2
[email protected]
Universidad de la República, Facultad de Ciencias, Departamento de Astronomı́a, Iguá 4225, 11400 Montevideo, Uruguay
Universidad de la República, Facultad de Ciencias, Laboratorio de Paleobiologı́a, Iguá 4225, 11400 Montevideo, Uruguay
232
Posters
Planetary Systems
PS -3:
#40
Photometry of Hot-Jupiters Type Exoplanets in Transiting Systems
Hickel, G. R.1 ; Siqueira, M. F. F. T.B2
The current project aims find candidates for temporal high resolution and multiband photometry at SOAR
(Southern Astrophysical Research Telescope) of exoplanets such as Hot-Jupiters in transiting planetary systems. The number of exoplanets discovered in transiting planetary systems significantly expanded in the
last 3 years, due the great performance of COROT and KEPLER satellites. Many of these discovered exoplanets are Hot-jupiters type, gas giants like the jovian prototype, orbiting their host star with lesser distances
than Mercury does in relation to the sun. Most of them need follow-up in transiting observations to refine
orbital and physical parameters. The temporal high resolution photometry (exposure time < 1% transiting
time) with small photometric erros (S/R > 1000) can be obtained on SOAR using the SOI and SPARTAN imagers. The multiband transiting photometry can even provide evidences of the exoplanet’s high atmosphere
features.
B
1
[email protected]
Universidade Federal de Itajubá
233
234
Stars & Stellar Systems
SSS -1:
#41
The BIOSUN project:an astrobiological approach to study the origin of life in the
context of the young Sun/solar stellar analogs
Abrevaya, X. C.B1 ; Hanslmeier, A.2 ; Leitzinger, M.2 ; Odert, P.2 ; Horvath, J. E.1 ; Ribas, I.3 ; Galante, D.1,4 ; Porto de
Mello, G. F.5
During the early ages of the Earth the magnetic activity of the young Sun was much stronger than the observed from the present Sun, in particular causing proportionally higher amounts of radiation emitted below
1700 Å. Such enhanced particle/high-energy radiation fluxes play a role in the evolution of planetary atmospheres and therefore on their surface conditions. Moreover, it is supposed that life arose on the Earth in
this environment, therefore it is thought that radiation could have had an important role in the origin and
evolution of life. Interestingly, solar stellar analogs could provide some relevant information about the characteristics of the Young Sun (age < 0.8 Gyr) which could allow the investigation of the radiation environment
of the early Earth among other planetary bodies. The objective of this project is to focus on the radiation
emission features of the young Sun through solar stellar analogs (mainly based on the data obtained by “The
Sun in Time” project) to characterize the radiation environment of the early Earth and other planetary bodies of the Solar System that are or could have been potentially inhabited by life as we know it, in particular
considering Venus, Earth, Mars and Europa and their early evolution. The next step will be to reproduce this
radiation environment under laboratory conditions to explore: 1) Whether cells could survive at that level
of radiation on the early Earth confronting that with the hypothesis that first cells could have arose around
3.8-3.5 Gyr ago according to the microbial fossil record. Additionally, the environments of Mars and Europa
will be tested; 2) The possibility of “transfer” of microorganisms between Earth, Mars and Venus at that time;
3) The formation, inflow and outflow of some prebiotic molecules in the early planetary conditions. The
experimental approach will be carried out exposing microorganisms to simulated environments according
to the data obtained previously. The irradiation sources will be a solar simulator for UV radiation and a synchrotron accelerator for X-rays. Microorganisms selected are cyanobacteria (the oldest entries in the fossil
record, found in stromatolites) and halophilic archaea (UV-tolerant features, also found in modern stromatolites analogs of the older stromatolites on the Earth, the fact of their apparent longevity since they were
found in evaporites from Permian and Triassic and its link to martian evaporites).
B
[email protected]
Research Unit in Astrobiology (NAP-Astrobio), Institute of Astronomy, Geophysics and Atmospheric Sciences, Universidade de São
Paulo, São Paulo, Brazil
2 Institute of Physics, Karl-Franzens-Universität Graz, Graz, Austria
3 Institut de Ciencias de l’Espai , CSIC, Spain
4 Brazilian Center for Research in Energy and Materials (CNPEM) / Brazilian Synchrotron Light Source (LNLS), Campinas - SP, Brazil
5 Observatorio do Valongo, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
1
235
Stars & Stellar Systems
Posters
SSS -1:
#42
A long-term study of the Be star Mu Centauri in the L-band
Aguayo, G.B1,2 ; Martayan, C.2 ; Mennickent, R. E.1 ; Baade, D.3 ; Rivinius, T.2 ; Stefl, S.4 ; Fabregat, J.5
We present 10 L-band spectra of the Be star Cen obtained with the VLT ISAAC distributed along 1 year during
an epoch of relative photometric quiescence. We observe significant changes in emission line strength of
Bracket- and Pfund- lines relative to Humphreys lines. We interpret this variability as monotonic changes in
the opacity of the circumstellar envelope, moving from an optically thin to an optically thick condition. This
behavior is observed just prior to the triggering of a major outburst.
B
[email protected]
Universidad de Concepción, Departamento de Astronomı́a, Casilla 160-C, Concepción, Chile.
2 European Organisation for Astronomical Research in the Southern Hemisphere, Alonso de Cordova 3107, Vitacura, Casilla 19001,
Santiago 19, Chile.
3 European Organisation for Astronomical Research in the Southern Hemisphere, Karl-Schwarzschild-Str. 2, D-85748 Garching b.
Muenchen, Germany.
4 ESO/ALMA, The European Organisation for Astronomical Research in the Southern Hemisphere/The Atacama Large Millimeter/Submillimeter
Array, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago 19, Chile.
5 Observatorio Astronómico de Valencia, edifici Instituts d’investigació, Poligon la Coma, 46980 Paterna Valencia, Spain
1
236
Posters
Stars & Stellar Systems
SSS -1:
#43
Determination of Li abundance in Solar type stars of intermediate brightness
Eliana Maritza Amazo-GómezB1 ; Bosco Hernandez-Aguila2 ; Miguel Chavez Dagostino2 ; Emanuele Bertone2 ; Victor de
la Luz2
The determination ofthe Li abundance (ALi) in stellar atlnospheres is of fundamental importance in multiple contexts of contemporary astrophysics. On one hand, the Li present in stars with global subsolar chemical abundances provides a strong restriction on the abundance of this clement as a result of primordial
nueleosynthesis. On the other hand, Li is one of the few age indicators for field stars with convective envelopes. Additionally, Li abundance appear to be correlated with the presence of sub-stellar companions,
perhaps even more correlated than global chemical composition.
We present preliminary results of a project aimed at determining the Li abundances of an extended sample of solar like stars (spectral type G and lulninosı̀ty class V) of intermediate brightness. High resolution
spectroscopic data (R=65000) were obtained with the CANHiS Echelle Spectrograph on the 2.11n telescope
of the Guillermo Haro Observatory in Cananea, Sonora, Mexico. Measured equivalent Widths and appropiate model atmopsheres for each star have been incorporated into the LINEWIDTH the program to detelmine
the abundance of Li.
B
1
2
[email protected]
Universidad Nacional de Colombia
Instituto Nacional de Astrofı́sica, Óptica y Electrónica INAOE
237
Stars & Stellar Systems
Posters
SSS -1:
#44
H accretion disc maps of V2051 Oph along outburst: additional evidence in favor of
the mass-transfer instability model
Andrade, E.B1 ; Baptista, R.1
Dwarf novae (DNs) are mass-exchanging binaries showing repeated outbursts, lasting from days to weeks
and recurring on timescales from weeks to years, in which their accretion discs brighten by factors 20-100
either because of a thermal-viscous instability cycle in the accretion disc (the DI model) or as a consequence
of an instability in the mass-donor star leading to a burst of enhanced mass-transfer (the MTI model). While
the issue seemed to be settled in favor of the DI model, the last decade has progressively provided compelling
evidence in support of the idea that there is a group of DN the outbursts of which are powered by MTI.
V2051 Oph is one of the DNs yielding stronger evidence in favor of the MTI (Baptista et al. 2007). Here we
report eclipse mapping analysis of velocity-resolved (|v| = 400
1000 km/s) H light curves of V2051 Oph
on 4 consecutive nights along its 2002 July outburst, based on spectroscopy collected with the 1.5 m ESO
telescope. The outburst starts with a ring of enhanced emission at the circularization radius, which spreads
inwards and outwards with velocities of
0.89 km/s and +0.16 km/s, respectively, to form an extended
bright disc in less than a day. The outburst maximum disc shows two asymmetric arcs reminiscent of the
spiral arms seen in other outbursting dwarf novae. The disc cools along the decline phase, with a cooling
wave that accelerates from
0.12 km/s (at ' 0.3 RL1 ) to
0.42 km/s (at ' 0.2 RL1 ) as it moves towards the
inner disc regions. The results are at odds with predictions of the DI model (cooling front deceleration), but
are in good agreement with the expected response of a viscous disc to a burst of dense, enhanced massaccretion through its sparse outer regions.
B
1
[email protected]
Universidade Federal de Santa Catarina
238
Posters
Stars & Stellar Systems
SSS -1:
#45
Fast and slow radiation-driven wind solutions using ZEUS-3D
Araya, I.B1 ; Curé, M.1 ; ud-Doula, A.2 ; Santillán, A.3
Currently, the theory of radiation–driven winds of massive stars posses three known solutions for the velocity
and density profiles of the stellar winds, namely: the fast, ⌦–slow and –slow solutions. In order to confirm
their stability we use a time–dependent numerical hydrodynamic code called ZEUS-3D, and then we compare their results with the stationary solutions from our numerical hydrodynamic code. ZEUS-3D needs an
initial trial solution to start to integrate, for this we use the stationary solution (from our code) or a –law
for the velocity field. In both cases we obtain the same results. Fast and both slow stationary solutions are
attained in ZEUS-3D and are all stables. Furthermore, there is a very good agreement with the velocity and
density fields from ZEUS-3D and our code, having differences between the terminal velocities lower than
3%.
In addition, we found that ZEUS-3D is very sensitive to the boundary conditions (base density and velocity
profile), in some cases we obtain kinks in the velocity profiles, similar to the ones obtained by Madura et al.
(2007) for stars with high rotation. We conclude that these kinks are because the initial trial solution is “far”
from the stationary solution.
Currently, we are exploring the effects of small perturbation at the base of the wind in order to study possible
transitions or oscillations between –slow and fast solutions.
B
1
2
3
[email protected]
Universidad de Valparaı́so, Chile
Penn State Worthington Scranton, USA
Universidad Nacional Autónoma de México, México
239
Stars & Stellar Systems
Posters
SSS -1:
#46
Effects of enhanced neutrino emission on the evolution of low-mass stars
Arceo-Diaz, S.B1 ; Schroeder, K-P.2 ; Zuber, K.3
With a laboratory limit of 3.2 ⇥ 10
11
µB , provided by Beda et. al. (2011), almost ten times larger than the one
currently predicted by Astrophysics, the neutrino magnetic dipole moment is a property out of the standard
model that remains unverified. Its existence has a important impact on the evolution and internal properties
of stars, as it has been already discussed by several authors, as it enhances the emission of neutrinos, via
plasmon decay, that can take energy away from dense stellar matter.
We use the well tested Eggleton code for stellar evolution to analyze the consequences of this enhanced
neutrino emission in the evolution of low mass stars, (internal structure and observable parameters) from
main sequence to the horizontal branch. We focus, on particular, on the possible differences in tip-RGB
luminosity for stellar models of around one solar mass and different metallicities, for different rates of enhanced neutrino cooling, at the eve of the Helium flash. To calculate the plasma-neutrino emissivity we use
the currently most accurate fitting formula, Kantor et. al. (2007), and consider the prescription of Raffelt et.
al. (1992) for the nonstandard contribution to the neutrino vector current. Finally, we comment on the impact of nonstandard neutrino emission on the calibration of the Reimmers mechanism for not dust-driven
mass loss in red giants and the possibility that standard ingredients of stellar theory, as chemical abundances
and rotation of the stellar core, can be responsible for the changes attributed to nonstandard neutrino emission.
B
1
[email protected]
Departamento de Astronomia, Universidad de Guanajuato, Mexico.
240
Posters
Stars & Stellar Systems
SSS -1:
#47
Wind study of B supergiants stars
Arcos, C.B1 ; Curé, M. 1 ; Kanaan, S.1
The estimation of the stellar and wind parameters of the B supergiants stars, give us important information
to understand the evolution of these. In recent years, different codes have been developed based on the
radiation-driven wind theory to estimate such parameters. It is known from previous studies that the A nonrotating (or slow rotation) supergiant stars can have two types of solution: one fast and one slow. Here we
study the two types of solutions for the B supergiant star: HD41117, using the FASTWIND code with beta law
and then modified-FASTWIND code that use the hydrodynamics from HYDWIND code).
B
1
[email protected]
Universidad de Valparaı́so, Chile.
241
Stars & Stellar Systems
Posters
SSS -1:
#48
On magnetic fields in barotropic stars
Armaza, C.B1 ; Reisenegger, A.1 ; Valdivia, J. A.2 ; Marchant, P.1,3
Although barotropic matter does not constitute a realistic model for magnetic stars, it would be interesting
to confirm a recent conjecture that states that magnetized stars with a barotropic equation of state would be
dynamically unstable (Reisenegger 2009). In this work we construct a set of barotropic equilibria, which can
eventually be tested using a stability criterion. A general description of the ideal MHD equations governing
these equilibria is summarized, allowing for both poloidal and toroidal magnetic field components. A new
finite-difference numerical code is developed in order to solve the so-called Grad-Shafranov equation describing the equilibrium of these configurations, and some properties of the equilibria obtained are briefly
discussed.
B
[email protected]
Instituto de Astrofı́sica, Facultad de Fı́sica, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 782-0436 Macul,
Santiago, Chile
2 Departamento de Fı́sica, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
3 Argelander Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, D-53121, Bonn, Germany
1
242
Posters
Stars & Stellar Systems
SSS -1:
#49
Searching for cyclical period variations in cataclysmic variable stars
Bernardo BorgesB1 ; Raymundo Baptista2 ; Alexandre de Oliveira3
Cataclysmic variables (CVs) are close binary systems where the late-type star (the secondary) overfills its
Roche lobe and transfers matter to a white dwarf (the primary) via an accretion disc. In this poster we report
some results of the search of cyclical period variations in three cataclysmic variables: UU Aqr, V2051 Oph and
VZ Scl (orbital periods of 3.9, 1.5 and 3.5 hours, respectively). These systems were monitored from 2008 to
2013 at Observatório do Pico dos Dias (OPD/LNA, Brazil) as part of long-term project to detect/characterize
cyclical period variations in CVs. Times series of high speed CCD photometry were obtained using the 0.6 m
and 1.6 m telescopes at OPD. We measured new white-dwarf mid-eclipse timings and combined them with
published measurements to construct updated observed-minus-calculated (O-C) diagrams. The UU Aqr OC diagram covers 24 years of observations and presents a 26 yr modulation with semi-amplitude of 47 s. The
V2051 Oph data cover 35 years of observations and the new timings show significant deviations from the
published linear plus sinusoidal ephemeris (22 yr modulation with a semi-amplitude of 17 s), indicating that
the variation is not strictly periodic. We are unable to detect period changes in VZ Scl due to short coverage
(less than one decade). We discuss the observed modulations in UU Aqr and V2051 Oph in context of the
two current explanations for the phenomenon: magnetic activity in the secondary star and the presence of
a third body in the system.
B
1
2
3
[email protected]
UFSC/Araranguá,Brazil
UFSC, Brazil
UNIVAP, Brazil
243
Stars & Stellar Systems
Posters
SSS -2:
#50
Unveiling Type IIb Supernova Progenitors
Bufano, F.B1
Type IIb Supernovae are the final evolutionary stage of massive stars that were able to retain only a thin (<
⇠1
M ) H/He external envelope at the time of the explosion. The mechanism of mass-loss that made such final
structure possible and the nature of such progenitor stars are still open issues. We present the preliminary
results obtained from the study of a sample of Type IIb SNe. In particular, we present SN 2011hs, a IIb SN
with peculiar properties: very high velocities measured from the spectroscopic lines and a faint and narrow
bolometric light curve, pointing to a low-mass He core progenitor star, as confirmed by the comparison with
hydrodinamical models. Finally, we obtain evidences for a progenitor with a radius of the order of 500-600
R , corresponding to an extended star as in the case of SNe 1993J and 2011dh.
B
1
[email protected]
Universidad Andres Bello, Chile
244
Posters
Stars & Stellar Systems
SSS -2:
#51
Detailed differential chemical analysis of a poor metal star: new evidences about
planet formation
Carlos, M. G. C. C.B1 ; Meléndez, J.2 ; Milone, A. C.1
The present project emphasizes on the study of metal-poor stars, with and without planets, to investigate
the existence (or not) of a connection between anomalies in the chemical composition and the presence of
planets by inspecting the high resolution spectra (R = 65 000), in order to derive chemical abundances with
high precision using the differential technique. In this method, measurements of equivalent widths of the
target star are compared to a standard star with predetermined photospheric parameters that are similar
to those of the target star (effective temperature, surface gravity and metallicity). Therefore, we have compared the star HD111232 (standard) with HD020794, such that the first holds a hot Jupiter-type planet and
around the second one there are three super-Earths. These solar-type stars are moderately metal-poor and
had their spectra collected with the MIKE spectrograph at the 6.5m Magellan telescope in the Las Campanas
Observatory. Among the main results, we have derived the classical photospheric parameters and chemical
abundances of refractory and volatile elements with such a high precision, particularly with errors about 0.01
dex, which is essential for the study of chemical connection between planets and star. We have also added
to the differential method the spectral synthesis of molecular bands and atomic lines to recover abundances
of volatile elements such as carbon, nitrogen, oxygen, and potassium. We thus present the parameters effective temperature, surface gravity, metallicity [Fe/H], microturbulence velocity and differential elemental
abundances. For some elements, we have performed comparisons of the abundances measured by spectral
synthesis with those obtained directly through measurements of equivalent widths.
B
1
2
[email protected]
Instituto Nacional de Pesquisas Espaciais
Universidade de São Paulo
245
Stars & Stellar Systems
Posters
SSS -2:
#52
Characterization and search for periodicities on coronal mass ejections (CME)
occurrence
Cecatto, J. R.B1 ; Guedes, M. R. G.1
It is well known that coronal mass ejections (CME) are solar phenomena corresponding to huge amounts of
gas being ejected from solar atmosphere to the interplanetary space. Typical velocities of several hundred
to few thousand km/s have been measured to ejected CME with an average of about 470 km/s. In principle,
the CME rate of occurrence should accompany the solar cycle activity. However, a distinct behavior has
been observed since the decay phase of the 23rd cycle. We studied CME start times recorded by LASCO
experiment on board Soho satelite, during the period from 1996 up to 2012, to investigate and characterize
their occurrence. This period enclose since the beggining of 23th solar cycle till actual maximum phase of
cycle 24. Also, we search for periodicities on CME occurrence. Yet, we suggest possible interpretations to the
unexpected high rate of CME occurrence during the period of 2005-2008.
B
1
[email protected]
Astrophysics Division, National Institute for Space Research
246
Posters
Stars & Stellar Systems
SSS -2:
#53
On the origin of the wind variability of 55 Cyg
M. Haucke1 ; M. Kraus2 ; R. Venero1 ; S. Tomic2 ; L. CidaleB3 ; M. Cure4
The hot supergiant star 55 Cyg shows strong spectroscopic variability. Drastic changes in the P Cygni profiles
of hydrogen lines take place in a matter of hours. In order to understand the origin of this variability, we study
an extensive sample of spectroscopic observations taken at the Observatory of Ondrejov (Czeck Republic).
We model the wind of 55 Cyg with FASTWIND code and derive the relevant parameters. Then we discuss the
mechanisms that could lead to the variable nature of the wind.
B
1
2
3
4
[email protected]
Facultad de Ciencias Astronomicas y Geofı́sicas, UNLP, La Plata, Argentina
Observatory of Ondrejov, Czeck Republic
Instituto de Astrofı́sica de La Plata, CCT-La Plata, CONICET-UNLP, Argentina
Departamento de Fı́sica y Meteorologı́a, Facultad de Ciencias, Universidad de Valparaiso, Chile
247
Stars & Stellar Systems
Posters
SSS -2:
#54
The Study of Physical Parameters of Unclassified Stars with the B[e] Phenomenon
M. Boges Fernandes1 ; Cesar A. H. CondoriB1
During the last years, the models of stellar evolution have had huge advances, obtaining a good agreement
with the observations, thanks to the inclusion of ingredients like rotation, mass loss and different metallicities. However, despite these advances, there are some phases for stars of different masses that are short and
with few objects already identified, which are still poorly known. They are called transition phases and as
an example, we have the stars with the B[e] phenomenon. This phenomenon occurs in objects of different
evolutionary stages, as pre-main sequence stars of intermediate mass (Herbig Ae/Be), evolved stars of low
and high mass (compact planetary nebulae and supergiant stars) and symbiotic objects. However, most of
the stars with the phenomenon B[e] in the galaxy still have their physical parameters unknown, being called
of unclassified B[e] stars (unclB[e]). In this work, we will present the results of the analysis of high resolution spectra obtained with the ESO/FEROS for a sample of 6 galactic unclB[e] stars. We obtained spectral
atlas for all of these objects, deriving radial velocities, equivalent widths, and also estimating their physical
parameters and distance, allowing us a better knowledgement of the nature of these stars.
B
1
[email protected]
Observatório Nacional/MCT
248
Posters
Stars & Stellar Systems
SSS -2:
#55
The VVV Templates Project
B1
R. Contreras Ramos
1
; M. Catelan ; R. Angeloni1 ; I. Dékány1 ; C. Navarrete1 ; F. Gran1 ; A. Jordán1 ; J. Alonso-Garcı́a1 ;
R. K. Saito1 ; J. Borissova2 ; The VVV Templates Team
Until now, stellar variability in the near-IR has been a relatively ill-explored research field: in particular, the
number of high-quality light curves was very limited and, even worse, many variability classes have not yet
been observed in a sufficiently extensive way in the near-IR, so that good light curves are entirely lacking for
some such classes. Since VVV is the first ever large survey dedicated to stellar variability in the near-infrared,
the first problem we had to face has thus been the construction of a proper statistically significant database
of high-quality (i.e., template) near-IR light curves for a significant sample of stars taken to be representative
of the different variability classes under study. The main purpose of the VVV Templates Project is thus to
build a large database of well-defined, high-quality, near-IR light curves for variable stars of different types,
which will form the basis of the VVV automated classification algorithms.
B
1
2
[email protected]
Pontificia Universidad Católica de Chile
Universidad de Valparaı́so, Chile
249
Stars & Stellar Systems
Posters
SSS -2:
#56
Extensive MultiConfiguration calculations of oscillator strengths useful for
Astrophysics Applications
Cruzado, A.B1 ; Di Rocco, H. O.2 ; Marchiano, P. E.3
The goal of this work is to obtain oscillator strengths (gf ) of spectral lines of astrophysical interest.
On the one hand, by using appropiate codes, we theoretically obtain the gf values. This involves: i) calculation of radial functions by means the Hartree-Fock (HF) method or some of its different approximations,
ii) calculation of radial integrals, iii) calculation of atomic energy levels, and iv) obtaining of the spectrum,
which means, wavelengths, gf values, and transition probabilities of the lines.
On the other hand, we empirically obtain the gf values. This implies: i) obtaining of line wavelengths from
laboratory experiments, ii) calculation of atomic energy levels, and iii) obtaining of gf values and transition
probabilities of the lines.
The comparison of the gf values obtained theoretically by adopting different approximations to the general HF method, among themselves and with the empirical values, is itself a goal of our work.
In addition, we aim to estimate the effects of the uncertainties associated with obtaining gf values in the
calculation of stellar abundances. In the atmospheres of chemically peculiar stars, it is critical the accurate
determination of the abundance of some chemical elements, as well as their possible variations with the
time.
With this in mind, we begin our analysis with spectral lines observed in the spectrum of He-weak, Hestrong, HgMn, and Ap stars.
B
1
2
3
[email protected]
Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Argentina
Instituto de Fisica de Arroyo Seco, Universidad Nacional del Centro de la Provincia de Buenos Aires, Argentina
Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Argentina
250
Posters
Stars & Stellar Systems
SSS -2:
#57
A new method to disentangle the rotational velocities of stars: application to
main-sequence field Stars
Curé, M.B1 ; Rial, D. F.2 ; Cassetti, J.3 ; Christen, A.4
The projected rotational velocity v sin i is a fundamental observable quantity. In order to obtain the rotational
velocity distribution of a sample of v sin i, Chandrasekhar & Münch (1950) developed a formalism to obtain
this distribution under the assumption that rotational axes are uniformly distributed, but this method is not
usually applied due to an intrinsic numerical problem associated to the derivative of an Abel’s integral. An
alternative iterative method was developed by Lucy (1974) to disentangle the distribution function of this
kind of inverse problem, but this method has no convergence criteria.
Here we presented a new method to disentangle the distribution of rotational velocities, based on Chandrasekhar & Münch (1950) formalism. We obtain the cumulative distribution function (CDF) of the rotational velocities from projected velocities (v sin i) under the standard assumption of uniform distributed rotational axes. Through simulations the method is tested using a) theoretical Maxwellian distribution functions for the rotational velocity distribution and b) with a sample of about 16.000 main-sequence field stars.
Our main results are:
The method is robust and in just one step gives the cumulative distribution function of rotational velocities.
When applied to theoretical distributions it recovers the CDF with very high confidence.
When applied to real data, we recover the results from Carvalho et al. (2009) proving that the velocity distribution function of main–sequence field stars is non–Maxwellian and are better described by Tsallis or
Kaniadakis distribution functions.
B
1
2
3
4
[email protected]
Universidad de Valparaı́so, Chile
Universidad de Buenos Aires, Argentina
Universidad Nacional de General Sarmiento, Argentina
Pontificia Universidad Católica de Valparaı́so, Chile
251
Stars & Stellar Systems
Posters
SSS -2:
#58
Self-consistent physical parameters for 5 intermediate-age SMC stellar clusters from
CMD modelling
Dias, B.B1,2 ; Kerber, L.1,3 ; Barbuy, B.1 ; Santiago, B.4 ; Ortolani, S.5 ; Balbinot, E.4
Stellar clusters in the Small Magellanic Cloud are fundamental pieces to study the chemical and dynamical
evolution of this neighbouring dwarf galaxy, enabling inspection of a large period covering ⇠10 Gyr. The
main goals of this work are the derivation of age, metallicity, distance modulus, reddening, core radius and
central density profile for each cluster, and place them in the context of the Small Cloud evolution. The
studied clusters are: AM 3, HW 1, HW 34, HW 40, Lindsay 2, and Lindsay 3, where HW 1, HW 34, and Lindsay 2
are studied for the first time. Optical colour-magnitude diagrams (V, B-V CMDs) and radial density profiles
were built from images obtained with the 4.1m SOAR telescope, reaching V ⇠ 23. The determination of
structural parameters were carried out applying King profile fitting. The other parameters were derived in a
self-consistent way by means of isochrone fitting, which uses the likelihood statistics to identify the synthetic
CMDs that best reproduce the observed ones. Membership probabilities were determined comparing the
cluster and control field CMDs. Completeness and photometric uncertainties were obtained performing
artificial star tests. The results confirm that these clusters (except HW 34, identified as a field fluctuation) are
intermediate-age clusters, with ages between ⇠1 and ⇠5 Gyr. Their metallicities follow the age-metallicity
relation by Pagel & Tautvaisiene (1998), with some spread as described by Parisi (2009) and Piatti (2011). In
particular HW 1, Lindsay 2, and Lindsay 3 are located in a region that we called West Halo. (Based on paper
by Dias et al. 2013, submitted to A&A).
B
1
2
3
4
5
[email protected]
IAG, Universidade de São Paulo
European Southern Observatory, Chile
Universidade Estadual de Santa Cruz
Universidade Federal do Rio Grande do Sul
University of Padova
252
Posters
Stars & Stellar Systems
SSS -3:
#59
V/R variations in Be shell stars
Escolano, C.B1 ; Carciofi, A. C.1 ; Rivinius, Th.2 ; Stefl, S.2
Be stars are rapidly rotating non-supergiant B type stars surrounded by a circumstellar disk. Both theoretical
and observational evidences converge toward the model of viscous decretion disk to describe their physics.
In that model, a geometrically thin disk - orbiting at Keplerian velocities - is formed by viscous diffusion of
the material ejected episodically from the central star.
From their build-up to their decay and even their disappearance, Be disks experience various dynamical
processes, on timescales of years. One of the most obvious indicator of their strong activity is the so-called
V /R variability, i.e. the quasi-cyclic variations of the violet and red emission peaks intensity observed in
neutral hydrogen lines. Such variability is generally explained by a global oscillation of the disk, forming a
one-armed spiral density perturbation precessing around the central star.
Some Be stars exhibit sharp absorption troughs in their Balmer and metallic lines; they are classified as
shell stars. Shell lines are usually found in Be stars observed with their disk edge-on, suggesting that the difference between ’normal’ and ’shell’ Be stars might be purely geometric. Interestingly, shell lines also exhibit
variations of their width and depth as the disk rotates. Those variations, as well as the V /R variations evoked
previously, are the spectroscopic translation of the structure and dynamics of Be disks. As a matter of fact,
studying shape variations of various lines, formed in different regions, might provide valuable informations
about the physics of the disk.
I will present the results of an analysis performed with the fully-3D radiative transfer code HDUST. The
analysis is focused on V/R variations of hydrogen Balmer lines in shell stars. By applying Gaussian fits to
the line profiles computed with HDUST, we are able to quantify their width, their height and their degree of
asymmetry, all indicative of the physical conditions in their formation region. The same treatment will be
applied to the observed spectra of ⇣ Tau and 48 Lib - two well-known shell stars vastly studied by our group and compared to simulations.
B
1
2
[email protected]
Institute of Astrophysics and Geophysics (IAG), São Paulo University (USP), Brasil
ESO, Santiago, Chile
253
Stars & Stellar Systems
Posters
SSS -3:
#60
Classical Cepheids from long-baseline interferometry: diameters, distances,
circumstellar envelopes and binarity
Gallenne A.B1 ; Kervella P.2 ; Mérand A.3 ; Breitfelder J.2,3 ; Gieren W.1
Optical interferometry is the only technique giving access to milli-arcsecond resolution at infrared wavelengths. For Cepheids, this is a powerful and unique tool to measure distances in a pseudo-geometric way,
and probe the close circumstellar environment. While the mean angular diameter allow us to probe the
pulsation mode, its angular and linear variation can provide the distance to the star. Independent distance
measurements are particularly interesting because classical Cepheids are used as primary distance indicator in the local group. Interferometry also enables to probe the close environment of these stars, and so
study their circumstellar envelope (CSE) and the companions. The characterization of these CSEs is particularly important as they give access to the present mass-loss rate of Cepheids. These CSEs were probably
formed through past or ongoing mass loss, possibly generated by shock waves in the pulsating atmosphere
of the Cepheid. Their presence can also biased the distance estimate in the Baade-Wesselink method. Finally, when Cepheids are in binary system, we can investigate their age and evolution, estimate the mass
and distance, and constrain theoretical models. However, most of the companions are located too close to
the Cepheid (⇠ 1
40 mas) to be observed with a 10-meter class telescope. The only way to spatially resolve
such systems is to use long-baseline interferometry.
B
1
2
3
[email protected]
Universidad de Concepción, Departamento de Astronomı́a, Casilla 160-C, Concepción, Chile
LESIA, Observatoire de Paris, CNRS UMR 8109, UPMC, Université Paris Diderot, 5 Place Jules Janssen, F-92195 Meudon, France
European Southern Observatory, Alonso de Córdova 3107, Casilla 19001, Santiago 19, Chile
254
Posters
Stars & Stellar Systems
SSS -3:
#61
A Study on the Universality and Linearity of the Leavitt Law in the LMC and SMC
Galaxies
A. Garcı́a-VarelaB1 ; B. E. Sabogal1 ; M. C. Ramı́rez-Tannus1
The universality and linearity of the Leavitt law are hypotheses commonly adopted in studies of galaxy distances using Cepheid variables as standard candles. In order to test these hypotheses, we obtain slopes of
the Leavitt law using linear regressions of fundamental-mode Cepheids observed by the Optical Gravitational Lensing Experiment project in the Magellanic Clouds. We find that the slopes in V I-bands and in the
Wesenheit index behave exponentially, indicating non-linearity. We also find that the slopes obtained using
long-period Cepheids can be considered as universal in the V I-bands, but not in the Wesenheit index.
B
1
[email protected]
Universidad de los Andes, Departamento de Fı́sica, Cra. 1E No. 18A-10, Edificio Ip, A.A. 4976, Bogotá, Colombia
255
Stars & Stellar Systems
Posters
SSS -3:
#62
High-frequency quasi-periodic oscillations in X-ray binaries: clues from their
amplitude and coherence
Claudio GermanàB1
The twin-peak high-frequency quasi-periodic oscillations observed in the power spectra of several Low Mass
X-ray Binaries (LMXBs), display central frequencies typical of the orbital motion time-scale close to the compact object. Thus, such modulations could arise from the energy released by accreting clumps of matter
interacting with the strong gravitational field of the compact object. HF QPOs are characterized by their
central frequency ⌫, root mean square amplitude (rms) and coherence Q = ⌫/ ⌫, where
⌫ is the width
of the peak. Here we investigate on the characteristic behavior of both the rms and Q observed in several
sources and highlight mechanical proprieties of the accreting material.
B
1
[email protected]
Departamento de Fı́sica, Universidade Federal do Maranhão, São Luı́s, Brazil
256
Posters
Stars & Stellar Systems
SSS -3:
#63
Rotational Properties of A-Type Stars
Monica GrossoB1 ; Hugo Levato1
El objetivo de este trabajo es presentar un analisis estadıstico completo y detallado de la rotacion de la
mayor muestra posible de estrellas A del Bright Star Catalogue (BSC) , utilizando mediciones de la rotacion
realizadas mediante la aplicación de una tecnica precisa y simple para medir las velocidades de rotacion
proyectada habida cuenta de las falencias senaladas en gran parte de la literatura sobre las dificultades para
medir vsini (velocidad de rotación proyectada). Para ello se han observado más de 800 estrellas de tipo
espectral A mas brillantes que magnitud V=6.5. Se han reducido los datos usando las tecnicas usuales de
IRAF y se ha medido el parámetro vsini usando el método DiGoLeG de Dıaz et al.(2011) que hace uso de la
Transformada de Fourier del máximo de la Funcion de Correlacion Cruzada para medir vsini. Se amplı́a la
muestra con los datos de Royer et al.(2002ab) y se analiza estadı́sticamente la muestra ampliada de 1900 objetos presentando las distribuciones observadas de las velocidades de rotacion axial para las distintas clases
de luminosidad y las distribuciones de la velocidad de rotación verdadera V que surge de deconvolucionar la
distribucion de vsini. El trabajo presenta datos de la rotacion para 223 estrellas cuyos valores de rotación se
desconocı́an previamente. Tambien cabe mencionar que durante la investigación se detectaron 13 binarias
espectroscópicas a las cuales se les calculo la rotacion a cada componente.
B
1
2
[email protected]
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
CONICET-UNSJ
257
Stars & Stellar Systems
Posters
SSS -3:
#64
Comparison of optical/near-infrared light-curve properties of the Cepheid Instability
Strip pulsating variables
Hajdu, G.B1 ; Dékány, I.1 ; Catelan, M.1,2
The ongoing ESO public survey, the Vista Variables in the Vı́a Lactea (VVV) maps about 520 square degrees
of the Galactic bulge and the disc in five near-infrared bands. Besides providing us with an unprecedented
map of the bulge and the disc, it also conducts a multi-epoch survey in the K band aimed at discovering
and characterizing hundreds of thousands of variable stars, many of which belongs to the classical Cepheid
Instability Strip classes ( and Type II Cepheids, RR Lyrae stars). For the first time, VVV data will enable us
to trace the structure of the spiral arms behind the bulge. This task will be largely depend on the Cepheid
variables, but a careful, robust distinction between them and the Type II Cepheids has to be made. Although
the period-luminosity relationships of these classes are accurately calibrated, no established classification
scheme of variables depending solely on the near-infrared light curves have been published yet.
We use a sample of variable stars discovered in the bulge by the optical microlensing surveys (OGLE, MACHO, EROS), common with the VVV survey to systematically compare the optical and K-band light-curve
properties of different classes pulsating variable stars. Knowing these parameters allow us to properly classify individual stars (based solely on VVV data), to map the regions of the Galaxy behind the Bulge. We pay
special attention to stars pulsating simulatenously in multiple modes (bump and beat Cepheids, RRd stars),
as the modeling of pulsations can provide accurate stellar parameters for these variables.
B
1
2
[email protected]
Instituto de Astrofı́sica, Pontificia Universidad Católica de Chile - Santiago, Chile
The Milky Way Millenium Nucleus, Santiago, Chile
258
Posters
Stars & Stellar Systems
SSS -3:
#65
White dwarfs in the Javalambre Physics of the Accelerating Universe Survey
A. KanaanB1 ; Navarro, E. A.2 ; Daflon, S.3 ; Pereira, C. B.3 ; Borges, M.3 ; Villegas, T. A.3 ; Gonçalves, D. R. G.4 ; Martins, S. L.4 ;
Marcolino, W.4 ; Ribeiro, T.5 ; Ederoclite, A.6 ; JPAS Collaboration
White dwarfs are the end state of all main sequence stars less massive than 8M , which means that 98% of all
stars will end up as white dwarfs. First and foremost, J-PAS will allow us to discover many new white dwarfs.
It will go deeper than SDSS; most of SDSS spectroscopically confirmed white dwarfs have a magnitude below
20.5, while J-PAS will be complete (5 detections) down to 22.5 in each filter. So we should see white dwarfs
2.5 times farther than SDSS and therefore the total volume will be (2.53 - 1 = 14.6 times larger. By definition
every object in J-PAS will be spectroscopically observed, while in SDSS only chosen objects had their spectra
taken, so our white dwarf sample will also be much more complete than SDSS. We expect to increase the
total number of white dwarfs from approximately 20,000 to 300,000. Among our goals are the study of the
white dwarf luminosity function and the mass distribution.
B
1
2
3
4
5
6
[email protected]
Departamento de Fı́sica, Universidade Federal de Santa Catarina
Instituto de Astrofı́sica de Andalucı́a
Observatórion Nacional, Ministério de Ciência e Tecnologia
Observatório do Valongo, Universidade Federal do Rio de Janeiro
Universidade Federal de Sergipe
Centro de Estudios de Fisica del Cosmos de Aragón
259
Stars & Stellar Systems
Posters
SSS -3:
#66
Line Identification in the Sun’s Spectrum
Kitamura, J. R.B1 ; Martins, L. P.1
Synthetic stellar spectra are extensively used for many different applications in astronomy, from determining
atomic parameters of new observed stars to the study of the stellar populations of galaxies. One of the inputs
for the codes that generate these synthetic spectra are atomic and molecular lines lists, which contain the
atomic parameters of the absorption lines that should appear in each spectrum. Although these lists contain
million of lines, very few of them were actually measured in laboratory. The consequence is that for many
lines the errors in the parameters can be as large as 200%. Besides that, we do not know all the lines that
appear in the stars. Even for the Sun, our closest and most studied star, the synthetic spectra misses many
lines. This is one of the main reasons we still cannot reproduce the spectrum of observed stars. In this
project we will develop a careful strategy to compare the synthetic and observed spectrum of the Sun to try
to identify and quantify the lines still missing in the models. We will also try to identify lines with large errors
in the atomic parameters, as for example, lines in which the central wavelength is wrong.
B
1
[email protected]
Universidade Cruzeiro do Sul
260
Posters
Stars & Stellar Systems
SSS -3:
#67
Pre-main sequence evolutionary tracks and isochrones in color-magnitude diagrams
Landin, N. R.B1 ; Mendes, L. T. S.2 ; Vaz, L. P. R.3
Evolutionary tracks are widely used to estimate masses of stars. Isochrones are specially used in determining
ages of stars in binary systems and in stellar clusters. We present non-gray, pre-main sequence evolutionary tracks and isochrones in theoretical and observational Hertzsprung-Russel diagram for Johnson-Cousins
(UBVRI), Johnson-Glass (JHKL) and CTI/CTIO. Theoretical evolutionary tracks from fully convective configuration to a given configuration in main sequence were generated by ATON 2.4 code for a range of masses
and chemical compositions. By using color-temperature relations and bolometric corrections available in
literature, we converted theoretical pre-main sequence evolutionary tracks and isochrones to their counterparts in color magnitude diagrams. We obtained grids of tracks and isochrones for low-mass stars with
different values of metallicity (Fe/H), including the solar one. We present a comparasion between tracks and
isochrones in the color-magnitude diagram obtained with different color-temperature relations and bolometric corrections. Finally, we used our new evolutionary tracks and isocrhones in color-magnitude diagram
to estimate masses and ages of the pre-main sequence stars of the NGC 2264 young cluster. The resulting
mass distribution of the bulk of NGC 2264 population is in the range 0.1-0.6M and the mean age of stars’
cluster is 3.5 Myr, which is in agreement with other works.
B
1
2
3
[email protected]
Universidade Federal de Viçosa - Campus UFV Florestal
Departamento de Fı́sica, Universidade Federal de Minas Gerais
Departamento de Engenharia Eletrônica, Universidade Federal de Minas Gerais
261
Stars & Stellar Systems
Posters
SSS -4:
#68
Unveiling optical properties of the high mass X-ray binary XMMU J054134.7-682550
from spectroscopy
Lopes de Oliveira, R.B1 ; Placco, V. M.2,3
XMMU J054134.7-682550 is an X-ray source located in the Large Magellanic Cloud. Based on its X-ray properties, and from optical and near-infrared photometry, it was assumed to be a Be/X-ray binary. In this work
we present the characterization of its optical counterpart from an optical medium-resolution spectrum acquired with the 3.6-m New Technology Telescope. Photospheric lines along with strong emission lines from
the H and several transitions of iron show that the optical counterpart is a Be star with a dense or large
circumstellar disk. Thus, it is now conclusive that the system is indeed a Be/X-ray binary. Additionally, we
present an ongoing program which aims to improve the characterization of the system from optical and
X-ray observations.
B
1
2
3
[email protected]
Universidade Federal de Sergipe, Brazil
NOAO, USA
Universidade de São Paulo, Brazil
262
Posters
Stars & Stellar Systems
SSS -4:
#69
In search of precise isochronal ages: Monte Carlo and Bayesian Approach
Diego Lorenzo-OliveiraB1 ; Gustavo F. Porto de Mello1
Obtaining accurate ages for FGK stars is important to understand the Galactic structure and evolution as
well as the evolution of exoplanetary systems. We build a dense grid of isochrones and evolutionary tracks
aimed to identify, in several spectroscopic surveys, which are the most stellar reliable ages based on solid
statistics. For this, we calculate their probability distributions of isochronal age and fundamental parameters
such as mass, radius, radius (at ZAMS) and surface gravity through Monte Carlo simulations and Bayesian
inference. From these determinations, we will be able to derive a sample of MS and subgiant stars with
very accurate isochronal ages covering an extensive domain of ages, masses and metallicities. This sample
will be very useful for future observational follow-ups and, moreover, when applied to age-activity-rotation
relationships will enable the construction of robust age calibrations for solar-type stars. Such calibrations of
age and activity might contribute towards the establishment of firmer relations governing the evolution of
angular momentum in solar-type stars.
B
1
[email protected]
Observatório do Valongo, Universidade Federal do Rio de Janeiro
263
Stars & Stellar Systems
Posters
SSS -4:
#70
El Catalogo Bibliografico de Velocidades Radiales
Malaroda, S.B1 ; Levato, H.1 ; Galliani, S.1 ; Vega, L.1
Se presenta la ultima version, la numero 24, hasta el 31 de diciembre de 2012, del Catalogo Bibliografico de
Velocidades Radiales, iniciado por el grupo en 1991. Se analiza el incremento a lo largo de estos años de los
datos observacionales provenientes de grandes contribuciones instrumentales como el RAVE y el BRAVA. El
numero de entradas de la presente version supera las 300.000.
B
1
[email protected]
Instituto de Ciencias Astronomicas, de la Tierra y el Espacio. ICATE-CONICET, San Juan, Argentina
264
Posters
Stars & Stellar Systems
SSS -4:
#71
Atmospheric stratificatfication in NLTE of He and He in the Bp star a Cen
3
4
Maza, Natalia L.B1 ; Nieva, M. Fernanda2,3 ; Levato, Hugo1
Chemically peculiar stars offer unique conditions to investigate difussion processes in stellar atmospheres.
The analysis of their spectra is, however, quiet challenging. Such stars present not only several hundred
of additional lines in comparison with normal stars due to abundance anomalies. Also, because of diffusion
processes, a stratification of the chemical species can affect the stellar atmosperic structucture and the spectral line formation.
We have analyzed a high-resolution and high-S/N UVES spectrum of the Bp star a Centauri (He- variable)
by means of state-of-the-art non-LTE spectral synthesis. Atmospheric paramteres were determined in an
iterative way via ionization equilibria of OI/II and FeII/III and the matching of several Balmer lines simultaneously. Because of chemical stratification and the presence of 3 He, the He lines are not matched with a
standard model atmosphere. A new He model atom accounting for the 3 He isotope and an empirically solution for the He stratification in the line-formation calculations allow us to characterise for the first time the
He lines of this star in a more realistic manner than do classical models. This non-trivial step is necessary to
perform a consistent spectral analysis of trace species, which will be done next.
B
1
2
3
[email protected]
Instituto de Ciencias Astronómicas, de la Tierra y del Espacio (ICATE), San Juan, Argentina
Remeis-Sternwarte & ECAP, University of Erlangen-Nuremberg, Germany
Institute of Astro- and Particle Physics, University of Innsbruck, Austria
265
Stars & Stellar Systems
Posters
SSS -4:
#72
Stellar models of low-mass, rotating pre-main sequence stars and the effects of an
imposed parametric magnetic field
Mendes, L. T. S.B1,3 ; Landin, N. R.2,3 ; Vaz, L. P. R.3
Rotating, pre-main sequence stellar models of low-mass stars have been computed with the ATON 2.3 stellar
evolutionary code, in which the effects of a large-scale, radially-varying parametric magnetic field are taken
in account. Those effects have been modeled according to method proposed by Lydon & Sofia (1995), in
which the magnetic field is treated as perturbation that changes the stellar structure equations. Here we report preliminary results on some stellar properties of those models, such as their position in the H-R diagram
and the resulting lithium burning.
B
1
2
3
[email protected]
Departamento de Engenharia Eletrônica, Escola de Engenharia, UFMG, Brazil
Departamento de Fı́sica, UFV, Brazil
Departamento de Fı́sica, UFMG, Brazil
266
Posters
Stars & Stellar Systems
SSS -4:
#73
Estimating the slope of average rotational axes stars in open cluster Pleiades
Dayvid de Sousa MirandaB1,2 ; Bráulio Batista Soares2 ; José Ronaldo Pereira da Silva2
The true rotational velocity of star, V , can be measured from the radius and period of the star. However,
determination of the angle of inclination of the rotational axis with the sight line i, is possible only in special
cases (eg, star or measured rotation period in binary systems with rotation and translation synchronized).
Often, the average equatorial speed, hV i, for a sample of stars is usually estimated by the ratio between the
projected average speed, hV sin ii, and the sine of the angle of inclination, hsin ii. The latter is assumed to
always equal to ⇡/4 = 0, 79 chance of random distribution of rotational axes irrespective of the particular
stellar population or sample. While this procedure has rarely led to discrepancies between theoretical models and the data observations. This work uses the radius star and the period of rotation to determine the
equatorial velocity actual best fit with the curve of distribution of velocities equatorial actual procedure by
which to determine the index q Tsallis entropy which allows to estimate the average hsin ii based on a sample
of radius, rotation periods and projected. This method is used to estimate the average hsin ii of a database
containing 217 stars in the Pleiades open cluster, whose rotation periods are available. The result shows an
excellent agreement with the observational data.
B
1
2
[email protected]
Instituto Federal do Maranhão
Universidade Estadual do Rio Grande do Norte
267
Stars & Stellar Systems
Posters
SSS -4:
#74
Near-IR Period-Luminosity relations for variable stars in omega Centauri
Navarrete, C.B1,2 ; Catelan, M.1,2 ; Alonso-Garcı́a, J.1,2 ; Contreras, R.1,2 ; Dékány, I.1,2
The VISTA Variables in the Vı́a Láctea (VVV) is an ESO public near-infrared variability survey expecting to
discover ⇠ 106 new variable sources. In order to perform an automated classification of those sources, welldefined Ks light curves are needed to be used as templates (VVV Templates Project, Catelan et al. 2011).
Under this context, omega Centauri is the most suitable globular cluster due to its large amount of known
variables. More than 30 hrs of VISTA observations and PSF photometry were used to derive the Ks light curves
for ⇠ 300 of known variable stars in omega Centauri (including RRab, RRc, SX Phoenicis, type II Cepheids,
Eclipsing Binaries and others) with almost complete phase coverage (more than 100 epochs), in the majority
of the cases for the first time in the near-IR.
The Period-Luminosity (PL) relation is a remarkable property of pulsating stars. At infrared wavelengths,
it has more advantages than the ones derived at visible bands: the interstellar extinction is lower and the
infrared luminosities are less sensitive to temperature changes (instability strip is narrower), so PL relations
are tighter, with low rms-dispersion. Considering that, PL relations in the near-infrared J and Ks bands were
derived for RR Lyrae, type II Cepheids and SX Phoenicis (more than 50 belonging to the cluster) omega Cen
variable stars. Each type was analyzed in order to find, if present, different pulsation modes, PL color or
metallicity dependence.
Our preliminary PL relations for each type, the PL slope behaviour and the possibility to determine the
omega Centauri distance modulus will be analyzed.
B
1
2
[email protected]
Instituto de Astrofı́sica, Facultad de Fı́sica, Pontificia Universidad Católica de Chile, Santiago, Chile
The Milky Way Millennium Nucleus, Santiago, Chile
268
Posters
Stars & Stellar Systems
SSS -4:
#75
High-ionization accretion signatures in compact binary candidates from SOAR
Telescope observations
Oliveira, A. S.B1 ; Rodrigues, C. V.2 ; Cieslinski, D.2 ; Jablonski, F.2 ; Gomes da Silva, K. M.2 ; Almeida, L. A.2
Exploration of transient astrophysical phenomena has been improved by the new generation of synoptic surveys and will soon receive a major impact when large synoptic surveys, like LSST, become available. Meanwhile, the increasing number of surveys made by small robotic telescopes represents a unique opportunity
for the discovery of new variable objects and also for the improvement of the samples of many classes of
variables. Here we show the results of our work on the search for spectroscopic signatures of high-ionization
mass accretion on variable objects of uncertain classification, using spectra obtained in 2012 with the Goodman High Throughput Spectrograph on the SOAR Telescope. Our goal is the discovery of new polars, a
subclass of magnetic Cataclysmic Variables (mCVs) with no accretion disk, and Close Binary Supersoft X-ray
Sources (CBSS), strong candidates to Type Ia Supernova progenitors. Both are rare objects and probe interesting accretion scenarios. Most of the candidates we observed came from the Catalina Real-Time Transient
Survey (CRTS), which incorporates data from 3 wide-field telescopes, in both hemispheres, reaching down
to 21 mag. Finding spectral features associated to high-ionization mass accretion, like HeII and inverted
Balmer decrement, constrains the CBSS or magnetic CV nature for the candidates, expanding the hitherto
small samples of these classes (specially CBSS) and allowing for detailed observational follow-up.
B
1
2
[email protected]
Univap
INPE
269
Stars & Stellar Systems
Posters
SSS -4:
#76
In the wake of ultraviolet sources observed by the Swift satellite
Pereira Santos, J.B1 ; Lopes de Oliveira, R.1 ; Luna, G. J. M.2
We present an ongoing project which aims to reveal the nature of the brightest unknown UV sources identified in observations carried out with the Ultraviolet/Optical Telescope onboard Swift. Our sample comprises
60 fields of 17’⇥17’ around symbiotic stars which were the main targets of Swift observations conducted by
our group during the past four years. Here we detail the pipeline procedure developed to identify UV sources
and search for variability in their flux, and the first results from the five fields already studied. The UV sources
identified are likely associated with cataclysmic variables, white dwarfs, and active stars. Additionally, we
present the complementary part of this investigation that intends to include optical spectroscopic followup, and mining of X-ray and infrared databases to support the characterization of UV sources.
B
1
2
[email protected]
Universidade Federal de Sergipe, Brazil
IAFE/UBA, Argentina
270
Posters
Stars & Stellar Systems
SSS -5:
#77
Abundance Analysis of CEMP RR Lyrae Stars
H. ReggianiB1 ; S. Rossi2 ; C. Kennedy3 ; T. C. Beers4
Among the stellar populations of the Galactic halo are a class of stars known as carbon-enhanced metal-poor
(CEMP) stars. These are metal-poor ([Fe/H] < 1.0) stars whose atmospheres exhibit large overabundances of
carbon ([C/Fe]
+0.7). The frequency of these stars increases with decreasing metallicity, and so by studying
their abundance patterns, one can begin to uncover details of the origins of the elements. There exist a
number of different classes of CEMP stars (Beers & Christlieb 2005) with specific abundance characteristics;
one of them is the CEMP-s class, which exhibit evidence of s-process element enrichment, widely belivied to
be resultant of mass transfer from a companion low-metallicity asymptotic giant branch (AGB) star, where
the production of carbon and s-process elements occurs.
Recent spectroscopic observations of metal-poor RR Lyrae stars have revealed that their typical abundance patterns are consistent with very metal-poor (VMP) and extremely metal-poor (EMP) giants and
dwarfs studied in the halo system of the Milky Way. Of particular interest is the recent discovery of a VMP RR
Lyrae that has large overabundances of carbon and the s-process elements.
In this work, we will show preliminaries results obtained with WiFeS observations 2.3m Siding Spring
Observatory telescope of a set of newly-identified CEMP stars that are known RR Ly stars. We seek to confirm classes of these likely CEMP-s stars and, eventually, test their abundances against new stellar evolution
simulations of CEMP stars.
B
1
2
3
4
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, Universidade de São Paulo
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, Universidade de São Paulo
Research School of Astronomy & Astrophysics, Australian Natinal University
National Optical Astronomy Observatory
271
Stars & Stellar Systems
Posters
SSS -5:
#78
Accretion and Activity on the PostCommonEnvelope Binary RR Cae
Ribeiro, T.B1,2 ; Baptista, R.3 ; Kafka, S.4 ; Dufour, P.5 ; Gianninas, A.5,6 ; Fontaine, G.5
Context. Current scenarios for the evolution of interacting close binaries – such as Cataclysmic Variables
(CVs) – rely mainly on our understanding of low mass stars angular momentum loss (AML) mechanisms.
The coupling of stellar wind with its magnetic field i.e., magnetic braking, is the most promising mechanism
believed to drive AML in these stars. There are basically two properties thought to drive magnetic braking;
stellar magnetic field and wind. Therefore understanding the mechanisms that drives AML requires a compressive understanding of both. Aims. RR Cae is a well known nearby (d = 20pc) eclipsing DA+M binary
with an orbital period of P = 7.29h. The system harbors a metal rich cool DA white-dwarf (WD) and a highly
active M dwarf locked in synchronous rotation. The metalicity of the WD suggest that wind accretion is taking place, thus providing a good opportunity to obtain the mass loss rate of the M dwarf component. We
aim to reach a better understanding of the AML mechanisms in close binaries by characterizing the relevant properties of the M dwarf component of this system. Methods. We analyzed multi-epoch time-resolved
high-resolution spectra of RR Cae in search for traces of magnetic activity and accretion. We selected a number of well known chromospheric activity indicators and studied their phase-dependence and long- term
behavior. Indirect imaging tomographic techniques were also applied in order to provide the surface brightness distribution of the magnetically active M dwarf. The blue part of the spectrum was modeled using state
of the art atmosphere model to constrain the WD properties and its metal enrichment. The latter was used
to improve the determination of the mass accretion rate from the M dwarf wind. Results. Doppler imaging of the M dwarf component of RR Cae reveals a polar feature similar to those observed in fast rotating
solar-type stars. Analysis of tomographic reconstruction of the H↵ emission line reveals the presence of two
components, one traces the motion of the M dwarf and is likely due to chromospheric activity while the
other clearly follows the motion of the WD. The presence of metals in the WD spectrum suggests that this
component arises from accretion of the M dwarf wind. A model fit to the WD spectrum provides Te↵ = (7260
± 250)K and log g = (7.8 ± 0.1)dex with a metallicity of < log[X/X ]
accretion rate of Ṁacc = (7±2)⇥10–16M · yr
B
1
2
3
4
5
6
1
(-2.8 ± 0.1)dex. This maps into a mass
onto the surface of the WD.
[email protected]
SOAR Telescope
Universidade Federal de Sergipe
Universidade Federal de Santa Catarina
Department of Terrestrial Magnetism
Département de physique - Université de Montréal C.P. 6128, Succ. Centre-Ville, Montréal, Quebec H3C 3J7, Canada
Homer L. Dodge Department of Physics and Astronomy University of Oklahoma, 440 W. Brooks St., Norman, OK, 73019, USA
272
Posters
Stars & Stellar Systems
SSS -5:
#79
High-resolution spectroscopic of red giants stars in NGC 2360
Sales Silva, J. V.B1 ; Pereira, C. B.1
Open clusters can be used to study the disk metallicity distribution and the radial abundance gradient of the
Galactic disk because they are among the few objects on the disk where the distances are well determined,
making the study of open clusters important to bring us consistent answers regarding the formation and
evolution of the two components of the disk (thick and thin disk). Moreover, open clusters are excellent
laboratories to test our knowledge of stellar structure and evolution, since the stars present the same age
and distance, thus reducing the uncertainties associated with field stars of the Galaxy. NGC 2360 is an open
cluster with 0.85 Gyr, with galactocentric distance equal to 9.28 Kpc and height equal to
30 pc (Salaris, et
al., 2004). We determine to 16 stars in the NGC 2360 using high resolution spectroscopy the atmospheric
parameters and the chemical composition for Fe, Ni, Cr, Ca, Mg, Si, Ti, Na, Al, Ba, Y, Zr, La, Ce and Nd with
measures of equivalent widths of absorption lines, and spectral synthesis for C, O and N. The spectra of our
stars were obtained with FEROS at the 2.2m ESO telescopes at La Silla (Chile). Atmospheric parameters and
abundances were determined using the local thermodynamic equilibrium atmosphere models of Kurucz
and the spectral analysis code MOOG. The spectroscopic study of NGC 2360 allowed us to confirm that the
binary stars NGC 2360-51 and NGC 2360-52 are belong to NGC 2360 and the discovery of one red straggler
star (NGC 2360-96). We also observed a slight overabundance of the elements generated by the s-process in
NGC 2360 with respect to field stars of the disk. According Mallorca et al. (2011) the overabundance of the
elements generated by the s-process occurs in young open clusters and may be linked to high-efficiency of
these nucleosynthesis in low-mass stars (< 1.5M ). However, this high-efficiency has not been explained
by the stellar evolutionary models. Additional observations and spectroscopic analysis of intermediate-age
open clusters (like NGC 2360) are necessaries to confirm the slight overabundances of s-process elements
with relation to field stars of the disk.
B
1
[email protected]
Observatório Nacional, Rio de janeiro, Brazil
273
Stars & Stellar Systems
Posters
SSS -5:
#80
Mapping of the Physicochemical Conditions of the Planetary Nebula Menzel 1
Santos, P.B1 ; Monteiro, H.1
We prensent a study of the physicochemical conditions of the planetary nebula Menzel 1 using the method
of spatially resolved spectrophotometric mapping. The data used in this study were collected in the Cerro
Tololo Inter-American Observatory (CTIO) 0.9 m telescope. Observations were made with traditional longslit spectroscopy with exposures taken for multiple parallel positions along the object in order to map it. The
separation of the 4” slits were of 4”. Initially, a data cube was created with the spectra obtained for each position of the slit. We used MPFIT - a software package that aims to find parameters that best fit the data to a
function - to fit gaussians to the emission lines observed in each pixel of the spatial direction, for each slit in
the data cube. We then reconstructed the image of the nebula for each a given emission line extracted from
the data cube, interpolating between observed slit positions. With these maps, we obtained the interestelar
extition from the H↵/H ratio pixel by pixel. We obtained the density map from the [SII]671.7nm/673.1nm
ratio and the temperature map from the [NII](654.8+658.4)nm/575.5nm ratio. Using the code NEAT (Nebular empirical analysis tool), the maps of the chemical abundance were calculated from the flux maps. These
maps provide a spatially resolved overview of the physicochemical conditions found in this object. From the
maps, we calculated mean values for the main diagnostics, which compared well with values from the literature, showing that we retrieved results from observations without spatial resolution. This method allows the
study of planetary nebulae in more detail than conventional methods.
B
1
[email protected]
Universidade Federal de Itajubá
274
Posters
Stars & Stellar Systems
SSS -5:
#81
Accretion disc mapping of the shortest period eclipsing binary SDSS J0926+36
Wagner SchlindweinB1 ; Raymundo Baptista1
AM CVn stars are ultracompact binaries (Porb < 65 min) where a hidrogen-deficient low-mass, degenerate
donor star overfills its Roche lobe and transfers matter to a companion white dwarf via an accretion disc.
SDSS J0926+36 is currently the only eclipsing AM CVn star and also the shortest period eclipsing binary
known. Its light curve displays deep (⇠ 2 mag) eclipses every 28.3 min, which last for ⇠ 2 min, as well as ⇠ 2
mag amplitude outbursts every ⇠ 100
200 d. Superhumps were seen in its quiescent light curve in some
occasions (Copperwheat et al. 2011), probably as a reminiscence of a (in some cases undetected) previous
outburst. Its eclipsing nature allows a unique opportunity to disentangle the emission from several different
light sources, and to map the surface brightness distribution of its hidrogen-deficient accretion disc with the
aid of maximum entropy eclipse mapping techniques. Here we report the eclipse mapping analysis of optical
light curves of SDSS J0926+36, collected with the 2.4 m Liverpool Robotic Telescope, covering 20 orbits of the
binary over 5 nights of observations between 2012 February and March. The object was in quiescence at
all runs. Our data show no evidence of superhumps nor of orbital modulation due to anisotropic emission
from a bright spot at disc rim. Accordingly, the average out-of-eclipse flux level is consistent with that of
the superhump-subtracted previous light curves. We combined all runs to obtain an orbital light curve of
improved S/N. The corresponding eclipse map shows a compact source at disc centre (Tb ' 16000 K) and
extended emission (Tb ' 4000 K) along the gas stream trajectory and the disc rim at R ' 0.44 a (a is the
orbital separation), suggesting gas stream penetration without bright spot formation.
B
1
[email protected]
Universidade Federal de Santa Catarina
275
Stars & Stellar Systems
Posters
SSS -5:
#82
Envelopes of Evolved Stars: Galactic and Magellanic Clouds B[e] Supergiants
Daiane Breves SeriacopiB1 ; Antonio M. Magalhães1 ; Alex C. Carciofi1 ; Antonio Pereyra2 ; Marcelo Borges2 ; Armando
Domiciano de Souza3 ; Francisco Araujo2 ; Jon Bjorkman4 ; Rocı́o Melgarejo Yrupailla1
B[e] Supergiants (B[e]SG) are massive stars with high rotation velocity and a non-spherical circumstellar
envelope. This envelope generates a net polarization observed in the light emitted from these objects. Spectropolarimetry is a powerful tool for mapping the structure of the envelope, since emission, absorption and
scattering processes are imprinted on the polarized flux. We present preliminary results of spectropolarimetry of Galactic Magellanic B[e]SG obtained with the 4 m Blanco telescope at Cerro Tololo and with the 8.2 m
VLT/UT1 telescope at Paranal. For data reduction, we used routines developed by the Polarimetry Group at
IAG-USP for the IRAF environment. Results of modeling R82 in the LMC are shown.
B
1
2
3
4
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas (IAG/USP) - Brasil
Observatório Nacional (ON) - Brasil
Université de Nice Sophia (UNICE) - France
University of Toledo - USA
276
Posters
Stars & Stellar Systems
SSS -5:
#83
Time-dependent nonextensivity arising from the rotational evolution of solar-type
stars
Silva, J. R. P.B1 ; Nepomuceno, M. M. F.1 ; Soares, B. B.1 ; de Freitas, D. B.2
The nonextensive formalism is a generalization of the Boltzmann-Gibbs Statistics. In this formalism the
entropic index q is a quantity characterizing the degree of nonextensivity, and is interpreted as a parameter of long-memory or long-range interactions between the components of the system. Since its proposition, in 1988, by Tsallis, this formalism has been applied to investigate a wide spectrum of natural phenomena. In stellar astrophysics, theoretical distribution function based on Tsallis nonextensive formalism
(q-distributions) has has been successfully applied to reproduce the distribution of V sin ⇠ i data for stars
from different stellar populations. In this paper, we investigate the time variation of the entropic index q
obtained from the distribution of rotation, V sin ⇠ i, for a sample of 254 rotational data for solar-type star
from 10 open clusters aged between 12.9 Myr and 2.6 Gyr. We have found that (1) there is an anti-correlation
between the entropic index q and the age of the clusters, and that the distribution of rotation V sin ⇠ i for
solar-type stars becomes extensive for an age of about 600 Myr; (2) the distribution of rotation V sin ⇠ i
as a function of age is well described by the nonextensive magnetic braking law derived by de Freitas & De
Medeiros (2013). Assuming that the parameter q is associated with long-memory effects, we also suggest that
the memory of the initial angular momentum of solar-type stars can be scaled by the entropic index q.
B
1
2
[email protected]
Universidade do Estado do Rio Grande do Norte
Universidade Federal do Rio Grande do Norte
277
Stars & Stellar Systems
Posters
SSS -5:
#84
Abundâncias de Zinco em estrelas do bojo Galáctico
B1
Silveira, C. R.
; Barbuy, B.1 ; Hill, V.2 ; Zoccali, M.3 ; Minniti, D.3 ; Renzini, A.4 ; Ortolani, S.5 ; Gómez, A.6 ; Dutra, N.1
O Zn é um dos elementos mais pesados da famı́lia do Fe e seu interesse ocorre por duas razões. Primeiro,
mostra uma caracterı́stica secundária em estrelas pobres em metal (Cayrel et al. 2004), sendo parcialmente
produzido pela adição de nêutrons, e traçar sua abundância ajuda a entender a sua nucleossı́ntese. Segundo,
e o mais importante, o Zn é o principal elemento de referência para derivar a metalicidade a partir das linhas
de absorção em quasares. Portanto, o estudo de sua abundância como uma função da metalicidade, permite
a comparação direta de sua abundância como função da distância e tempo das nuvens presentes entre nós
e os quasares. Dispomos de 55 espectros obtidos com o espectrógrafo UVES do VLT, com uma resolução R =
45000, na faixa de comprimento de onda de 480
680nm, que nos permite derivar as abundâncias de Zn das
linhas de ZnI em 481.0nm e 636.2nm. Podemos notar que tanto a abundância do zinco ([Zn/Fe]) da nossa
amostra como os valores de Reddy et al. (2003, 2006), Nissen et al. (2011) e Cayrel et al. (2004) crescem com
metalicidade decrescente, ou seja, de um valor alto em estrelas pobres em metais, chegando ao valor solar
em metalicidades maiores.
B
1
2
3
4
5
6
[email protected]
Universidade de São Paulo, IAG
Université de Sophia-Antipolis, Observatoire de la Côte d’Azur
Universidad Catolica de Chile, Departmento de Astronomia y Astrofisica
Observatorio Astronomico di Padova, Vicolo dell’Observatorio
Università di Padova, Dipartimento di Astronomia
Observatoire de Paris-Meudon
278
Posters
Stars & Stellar Systems
SSS -5:
#85
An study of v sin i distribution of Be stars
Camila Maria SitkoB1 ; Eduardo Janot Pacheco2 ; Marcelo Emilio1
In this work we present the distribution of v sin i of 268 Be’s stars from BeSS (Be Star Spectra) database. We
used two tecniques, the Fourier method and the FWHM (Full Fidth at Half Maximum) method and compared
our result between the methods and with the literature. For the analysis we made use of three absortion
lines of helium, they are 4026Å, 4388Å and 4471Å. We also estimate corrections for turbulance through an
minimization technique of our distribution results with the values found at literature. The correction was
applied for the values of v sin i not found at the literature. We concluded that the Fourier method give more
consistent values of the projected rotational velocities up to 400km/s.
B
1
2
3
[email protected]
UEL
IAG-USP
ON
279
Stars & Stellar Systems
Posters
SSS -6:
#86
Theoretical distribution function for rotations of field evolved stars
Soares, B. B.B1 ; Silva, J. R. P.1 ; Silva, M. P.1
The present study we compare the different distributions of V sin i, carried out on a large sample for field
evolved stars, obtained for different B V intervals with the named q-Maxwellian distribution model. Results
show a decreasing trend of the q parameter with increasing color-index B
V . Thus, q-Maxwellian appears
to be a more suitable instrument to scrutinize the rotational behavior of evolved stars.
B
1
[email protected]
Department of Physics, State University of Rio Grande do Norte
280
Posters
Stars & Stellar Systems
SSS -6:
#87
Stellar Parameters and Metallicities of a Sample of M dwarfs Hosting Planets
Souto, D.B1 ; Cunha, K.1 ; de la Reza, R.1 ; Ghezzi, L.1 ; Smith, V.2
M-dwarfs are an important component in both radial-velocity and transit searches for exoplanets, thanks
to the enhanced detectability of small planets due to low stellar masses, low luminosities, and small stellar
radii, as well as the fact that they are the most numerous stars in the Galaxy. The determination of stellar
parameters and chemical abundances of M-type dwarfs is challenging and remains relatively unexplored.
We present results for stellar parameters and metallicities for a sample of planet hosting M-dwarf stars from
a spectrum synthesis analysis of high-resolution spectra observed with CRIRES on the VLT between 1.588
and 2.33 microns.
B
1
2
[email protected]
Observatório Nacional - MCT
NOAO/ HQ,US
281
Stars & Stellar Systems
Posters
SSS -6:
#88
SN 2009N: Another Supernova between the Normal and Faint Type II-P SNe
Takats, K.B1
Type II supernovae are core-collapse SNe that are classified based on the presence of hydrogen in their spectra. Among them, type II-P SNe represent the most numerous class by far. Those within the subgroup of
subluminous II-P events are typified by fainter absolute magnitudes, lower expansion velocities and smaller
ejected Ni-mass than the majority of SNe II-P. However, only a couple of SNe falling into the ”gap” between
the subluminous and the normal SNe II-P populations have been discovered so far.
We present ultraviolet, optical and near-infrared photometric and spectroscopic observations of such object, SN 2009N in NGC 4487. The observed characteristics of SN 2009N (plateau length, spectral evolution,
expansion velocity, ejected Ni-mass) are compared to those of subluminous SNe and to those of another
intermediate-luminosity object, SN 2008in. We estimate the physical parameters of the progenitor at the explosion (explosion energy, progenitor radius, ejected mass) through hydrodynamical modelling of the main
observables and discuss the results.
B
1
[email protected]
Universidad Andres Bello
282
Posters
Stars & Stellar Systems
SSS -6:
#89
Differential chemical abundances of heavy elements in solar twins
Tucci Maia, M.B1 ; Melendez, J.1
In this work we present differential chemical abundances of neutron-capture elements (Z > 30) in solar
twins. We have obtained high resolution (R = 60, 000) and high S/N (> 100) spectra of solar twins in the
ultraviolet region (310-400nm) with the UVES spectrograph at the VLT/ESO. In the same configuration we
also observed that the Sun, that is our reference for the differential analysis, thus obtaining results with high
accuracy and precision. In the ultraviolet there is a large number of atomic transitions of heavy elements,
which allows the detailed study of the r and s processes. Our sample of solar twins covers a wide range of
ages, so it will be possible to study the temporal evolution of the neutron capture elements.
B
1
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas (IAG/USP)
283
Stars & Stellar Systems
Posters
SSS -6:
#90
Stellar differential rotation using planetary transits of starspots
Adriana ValioB1
When a planet transits its host star, spots and other features on the surface of the host star may be occulted,
causing small variations in the star light curve. Detailed analysis of these variations during planetary transits
provides a wealth of information about starspot properties such as size, position, temperature (i.e. intensity),
and magnetic field. By observing multiple transits, it may be possible to detect the same spot on different
transits and thus determine the stellar rotation. Assuming a rotation profile of the star with latitude, for
example similar to the Sun, the stellar differential rotation may be estimated. This study is performed using
the light curves of known planets detected by the CoRoT and Kepler satellites. Results from the analysis of
these lightcurves yields the stellar rotation and differential rotation that are presented here.
B
1
[email protected]
CRAAM - Mackenzie University
284
Posters
Stars & Stellar Systems
SSS -6:
#91
Infrared accretion disc mapping of the dwarf nova V2051 Ophiuchi in outburst and in
quiescence
Wojckiewicz, E.B1 ; Baptista, R.1
Dwarf novae are compact binary systems where a late-type star (the secondary) fills its Roche lobe and transfers matter to a companion white dwarf (the primary) via an accretion disc. They show outbursts which recur on timescales of weeks to years, where the accretion disc brightens by factors 20 to 100 either due to a
thermal-viscous instability in the disc (DI model) or due to an instability in the secondary which causes a
burst of enhanced mass-transfer (MTI model). A DI-driven outburst requires temperatures high enough to
<
ionize hydrogen Thot >
⇠ 10000K at outburst maximum, and Tcool ⇠ 7000K when the disc is in quiescence,
whereas in an MTI-driven outburst there is no temperature constraint.
Here we present time-series of fast photometry of the dwarf nova V2051 Oph in the J and H bands, obtained with the CAMIV at the 1.6 m telescope of Observatório Pico dos Dias/Brazil, during the decline of an
outburst in 2005 June, and in 2008 when the object was in quiescence. We modelled the ellipsoidal variations
caused by the secondary to infer its contribution to the J and H fluxes, and fitted stellar atmosphere models
to find a photometric parallatic distance of d = (111± 14)pc. At this short distance, the corresponding disc
temperatures in outburst are too cold to be explained by the DI model, underscoring the suggestion of Baptista etal. (2007) that the outbursts of this system are powered by MTI. We also present and discuss J and
H eclipse maps tracing the evolution of the disc surface brightness distribution during the decline from the
2005 June outburst.
B
1
[email protected]
Grupo de Astrofı́sica, Univerisade Federal de Santa Catarina
285
Stars & Stellar Systems
Posters
SSS -6:
#92
VVV Survey search for distant Cepheids in the inner Milky Way
Elenna CapoteB1,2 ; Istvan Dékány2 ; Dante Minniti2,3
The VVV Survey has been monitoring the inner disk and bulge of the Milky Way in the near-infrared since
2010. We are building a variability database that would contain a billion point sources in these regions.
Using the available data, we have started a search for distant Cepheid variable stars. The multicolor ZYJHKs
photometry allows us to estimate the individual reddenings, and the periods yield the intrinsic luminosities,
from which accurate distances can be obtained. The main aim of this project is to map the structure of the
Milky Way out to longer distances than has been possible before. We report initial results of this search in
bulge and disk fields which contain more than two dozen epochs of observations to date.
B
1
2
3
[email protected]
Massachusetts Institute of Technology
Instituto de Astrofisica, Pontificia Universidad Catolica de Chile
The Vatican Observatory
286
Posters
Stars & Stellar Systems
SSS -6:
#93
Stelar Activity in stars with planets from CASLEO spectra
Flores, M.B1 ; Buccino, A.2 ; Saffe, C.3 ; Mauas, P.4 ; González, F.5
In this work, we study the activity of a sample of stars with planets like nearby Jupiters (0.40<Mp<11 and
a<1 UA). We did a study at long-term from the index of Mount Wilson (S). For this, a set of espectra of high
resolution was taken and obteined between the years 2002 and 2010 with the spectrograph REOSC of the
telescope 2.15 m of CASLEO. In this study, we analyze the stars’ activity at long-term and its dependence
with several orbital parameters of the planet. Also, we compare these levels of activity with the asociated at
stars of equal type, espectral class and luminosity that don’t have planets.
B
1
2
3
[email protected]
Institute of Astronomical Sciences, Earth and Space
University of Buenos Aires
Institute of Astronomy and Space Physics
287
Stars & Stellar Systems
Posters
SSS -6:
#94
Chemical abundances and physical parameters of evolved stars with planets
Jofre, E.B1 ; Petrucci, R.2 ; Saker, L.1 ; Artur, E.1 ; Saffe, C.3 ; Gomez, M.1 ; Mauas, P.2
In this contribution we report homogeneous spectroscopic determinations of the effective temperature,
surface gravitiy, metallicity, projected rotational velocity and individual abundances for a large sample of
evolved stars with planets, as well as for a control sample of evolved stars not known to host planets. Among
other empirical relationships between planets and their host stars, we investigate the connection between
the chemical abundances of these evolved stars and the presence of giant planets. Implications for the primordial and the self-enrichment hypotheses are also discussed.
B
1
2
3
[email protected]
Observatorio Astronómico de Córdoba, Argentina
Instituto de Astronomı́a y Fı́sica del Espacio, Argentina
Instituto de Ciencias Astronómicas, de la Tierra y del Espacio, Argentina
288
Posters
Stars & Stellar Systems
SSS -7:
#95
Modeling Blue Horizontal Branch Stars
Santos, R. G.B1 ; Martins, L.1
The stars of the Blue Horizontal Branch (BHB) are characterized by having being through most of their evolutionary process and lost part of their external layers, leaving only a thin layer of hydrogen and a burning
Helium nucleus. This makes these stars very blue and hot, although old. They are present in many stellar
population systems (e.g. stellar clusters and elliptical galaxies), and their presence can induce errors in the
age determination of these objects using integrated spectra. The stellar population analysis technique using
integrated spectra is a very powerful tool nowadays, however stellar population models do not account for
the BHB stars. Because of that, the presence of these stars induces to the determination of younger ages
than expected for these systems. In this project we will create synthetic spectra for the BHB stars that can be
incorporated to the stellar population models to be used in spectral synthesis. Here we present an study of
the atmospheric parameters of these stars that will be used to create the synthetic spectra.
B
1
[email protected]
NAT - Universidade Cruzeiro do Sul, Brasil
289
Stars & Stellar Systems
Posters
SSS -7:
#96
An observational overview of the rotation in binary systems
Mattiuci, A. C.1 ; Santos, H. B. S.B1 ; Soares, B. B.1 ; Silva, J. R. P.1
Theoretical models of stellar angular momentum evolution predict that the distribution of stellar rotational
velocity can be altered by the presence of a binary companion. In the early stages of stellar formation, the
binary companion can decrease the time of magnetic star-disk coupling and influence the rate of rotation
which the star reaches the main sequence. After the stellar formation, the binary companion can produce
tidal torques that alters the angular momentum of the star. As a result, the evolution of the angular momentum of the binary stars are different from the one of the single stars. In this context, the accuracy of the models of stellar angular momentum evolution is constantly increased by comparing it with the observational
data. In the last few years, new technologies in the development of new instrumentation, and observational
techniques have considerably increased the number of catalogs of stellar rotation. In this work we use rotational data for about 3.000 binary stars from the literature to obtain an overview about the evolution of the
stellar rotational velocity in binary systems. We analyze the relationship between rotation and stellar radius,
X-ray luminosity, and the synchronization process in different stages of stellar evolution.
B
1
[email protected]
Universidade do Estado do Rio Grande do Norte
290
Posters
Stars & Stellar Systems
SSS -7:
#97
Mass loss from massive stars
Setia Gunawan, D. Y. A.B1 ; Cure, M.2
Massive stars in galaxies transfer huge amount of processed matter and energy into the interstellar medium
through their hot, dense and fast stellar wind, and through their often explosive ending. These processed
matter and energy in the interstellar medium will in turn influence further star formations. Knowledge about
the evolution and characteristic massive stars is therefore crucial in understanding the evolution of galaxies
and universe as a whole.
The fast dense wind from massive star is line-driven radiatively and is in-homogen/clumped. Models predicted that the clumping is stratified. We will briefly discuss the evidence of inconsistencies of result of massloss rate measurements derived using different diagnostics due to clumping, leading to over-estimation (by
up to a factor of ten) of the currently accepted mass-loss rate of massive stars. This is followed by discussion
on efforts to constrain the clumping stratification to establish the real mass-loss rates of massive stars.
B
1
2
[email protected]
ALMA JAO, Chile
Universidad de Valparaiso, Chile
291
Stars & Stellar Systems
Posters
SSS -7:
#98
Spectroscopy of the open cluster remnant candidate ESO429-SC02
Angelo, M. S.B1 ; Corradi, W. J. B.1 ; Santos Jr., J. F. C.1 ; Maia, F. F. S.1
In this study we intend to assess conclusively the physical nature of the open cluster remnant (OCR) candidate ESO429-SC02. In a previous work, the method of characterization devised by Pavani & Bica (2007) failed
to characterize the object as an OCR or as an asterism, classifying it as a possible OCR. To perform our anal0
ysis, we carried out multi-object spectroscopy of 31 stars in its inner area (r <
⇠ 4 ) using GMOS/GEMINI-S
(resolution R ⇡ 2000). We have cross-correlated (IRAF’s FXCOR task) our science spectra with 1962 templates
from ELODIE library and obtained heliocentric radial velocities, spectral types and metallicities. In our re-
search, we have employed 2MASS JHKs photometric data and retrieved proper motions from UCAC4. We
have derived individual distances via spectroscopic parallax and reddening values for our science stars. In
a star-by-star analysis we used the dispersion of the derived parameters as a measure of the star’s physical
connection. Preliminary results indicate that five stars are at approximately the same distance from the Sun
(hdi = 1.81 ± 0.05 kpc (s.d.)), have nearly solar metallicities (h [Fe/H]i = 0.039 ± 0.064) and quite consistent
heliocentric radial velocities (hVr i = 21.9 ± 9.6 km/s), although only three of them share common proper
motions (hµ↵ cos i =
0.77± 1.4 mas/yr; hµ i =
2.1 ± 2.5 mas/yr). Three other bright stars (J < 12.m 4)
present in ESO429-SC02 central field, but without observed spectrum, have proper motions components
values similar to these mean ones and, together with the other five candidate member stars identified, they
possibly form a coeval aggregate well fitted by a log (t/yr) = 8.8, Z = Z Padova isochrone (Bressan et al.
2012) with (m
M )0 = 11.m 2 and E(B
V ) ⇡ 0.m 1. Our nest step will be to cross-correlate our spectra with
synthetic spectra libraries in order to cover ELODIE’s “gaps”, in parameters space, specially in metallicity.
This way we aim to better constrain the list of probable members of ESO429-SC02.
B
1
[email protected]
ICEx/Physics Department, Universidade Federal de Minas Gerais
292
Posters
Stars & Stellar Systems
SSS -7:
#99
Collisions between Globular Clusters
Belloni, D. T.B1 ; Rocha-Pinto, H. J.2
The study of globular clusters plays an important role on our understanding of the Universe since these
systems are true laboratories for theories of stellar dynamics and evolution. Although the common, traditional astronomical knowledge about these systems picture them as homogeneous polytropes, made of
single stellar populations, the detailed photometrical study and chemical tagging of their constituent stars
suggest that some are far from being homogeneous systems. The discrepancies from the canonical picture
include double (or even triple) main sequences and/or red giant branches, larger than expected internal
chemical abundance scatter and unusual horizontal branch showing simultaneously extremely blue and red
stars. Some of these non-canonical clusters are now being seen as remmants of the nuclei of former satellite
galaxies of the Milky Way. A similar awkward extragallactic globular cluster (Scl-dE1 GC1) in the Sculptor
Group dwarf elliptical galaxy Scl-dE1 (Sc22), studied by Da Costa et al. has a half-light radius of 21.8 pc, an
absolute magnitude of MV =
6.7 and the cluster stellar population appears indistinguishable from that of
the parent galaxy. Da Costa et. al suggest that this object might have formed through the merging of star
clusters. This scenario for the formation of Scl-dE1 GC1 was succesfully reproduced by Assmann et al. with
a particle-mesh code. Since the globular cluster configuration correspond to a relatively small, relaxed gassfree stellar system supported by velocity dispersion, it is likely that a number of different objects, by means
of their formation path, could end up as globular-like systems, including some globulars formed by early
collisions of other globulars. We here study the outcomes of collisions between globular clusters under the
gravitational influence of a larger disk galaxy. We use the NBODY6 direct N -body code by Aarseth to check
under which conditions a close encounter of two globulars could disrupt them or lead to a merged, larger
globular. We check whether merged globulars have a peculiar luminosity profile right after the merger and
how much time it takes for a new relaxation.
B
1
2
[email protected]
Valongo Observatory, Federal University of Rio de Janeiro
Valongo Observatory, Federal University of Rio de Janeiro
293
Stars & Stellar Systems
Posters
SSS -7:
#100
Study of clustering in the stellar abundances space
Boesso, R.B1 ; Rocha-Pinto, H. J.1,2
The study of the stellar populations provides us with an understanding of the origin and evolution of the
Milky Way. The chemo-evolutionary history of the Galaxy is still preserved in the stellar abundance distributions. Since stars are formed from the interstellar medium and inherit these chemical abundances, it is
expected that the stars we observe today can be classified in chemical groups, in an analogous way to the
classification of biological species. The aim of this study is to find structures in the stellar abundances space,
obtaining stellar groups that had a similar chemo-evolutionary history, through the use of tree clustering
technique. We built tree classifications for large and classic abundance surveys in the literature: Edvardsson
et al. (1993); Fulbright (2000); Gratton et al. (2003a); Reddy et al. (2003); Reddy et al. (2006); Takeda et al.
(2008); Neves et al. (2009); Adibekyan et al. (2012). In this technique, the data are grouped hierarchically, so
that initially the number of clusters is identical to the number of observations and, by recursive clustering
of data by similarity, the number of clusters progressivelly decreases. This method allows us to analyze large
samples of stars and to obtain information about the enrichment history of the Galaxy. In this study we also
made use of a second tool, the PCA (Principal Component Analysis) method, and we apply this tool to stellar
abundances to analyze the history of star formation and the main processes of nucleosynthesis.
B
1
2
[email protected]
Observatório do Valongo, Universidade Federal do Rio de Janeiro
LIneA, Laboratório Interinstitucional de e-Astronomia
294
Posters
Stars & Stellar Systems
SSS -7:
#101
Old open clusters in the VVV Survey
Borissova, J.B1 ; et al.
We will report the discovery and analysis of new old infrared open cluster candidates projected in the bulge
area covered by VISTA Variables in the Via Lactea (VVV) ESO Large Public Survey. For relatively well populated cluster candidates we derived the fundamental parameters such as reddening, distance and age by
fitting the solar-metallicity Padova isochrones on the color-magnitude diagrams and spectroscopic parallaxes. Some important existing distributions such as distance of the cluster to the galactic center vs. age
distribution, open clusters age histogram, distance of the open clusters to the Sun vs. reddening, etc. are
complemented with the new sample and re-derived.
B
1
[email protected]
Universidad de Valparaiso, Chile
295
Stars & Stellar Systems
Posters
SSS -7:
#102
Phase Mixing in Popping Star Clusters
Candlish G. N.B1 ; Smith R.1 ; Fellhauer M.1 ; Gibson B. K.2 ; Kroupa P.3 ; Assmann P.1
As star clusters are expected to form with low star formation efficiencies, the gas in the cluster is expelled
quickly and early in their development: the star cluster “pops.” This leads to an unbound stellar system.
Previous N-body simulations have demonstrated the existence of a stepped number density distribution
of cluster stars after popping, both in vertical position and vertical velocity, with a passing resemblance
to a Christmas tree. Using numerical and analytical methods, we investigate the source of this structure,
which arises due to the phase mixing of the out-of-equilibrium stellar system as it evolves in a background
analytical potential. Considering only the vertical motions, we construct a theoretical model to describe
the time evolution of the phase space distribution of stars in a Miyamoto-Nagai disk potential and a full
Milky-Way type potential comprising bulge, halo and disk components, which is then compared with Nbody simulations. Using our theoretical model, we investigate the possible observational signatures and the
feasibility of detection.
B
1
2
3
[email protected]
Departamento de Astronomia, Universidad de Concepción, Chile
Jeremiah Horrocks Institute, University of Central Lancashire, Preston, UK
Argalander Institut fur Astronomie, Universitat Bonn, Bonn, Germany
296
Posters
Stars & Stellar Systems
SSS -7:
#103
Checking the consistency of physical parameters of open clusters: the case of NGC188
and M67
de Souza, C. C.B1 ; Kerber, L. O.1
Open cluster are fundamental pieces to calibrate the stellar evolutionary models, especially in the regime of
solar metallicity. Despite the large number of determinations of physical parameters for open clusters, there
is a lack of consistency tests to check these results. In this work we investigate this consistency in two classical
open clusters: NGC 188 and M 67. It is done by means of isochrones fitting in multiband colour-magnitude
diagrams, from optical (BVI) to the near-infrared (JHK). For this purpose we apply a numerical-statistical
method based on the likelihood statistics to find the best solutions. Our results point to the existence of a
sensitive dependence on the values of age, distance, reddening and metallicity depending on the choice of
wavebands as well as the adopted stellar evolutionary models. In particular we find differences in age that
can exceed 40%, even comparing results for the optical bands.
B
1
[email protected]
Universidade Estadual de Santa Cruz
297
Stars & Stellar Systems
Posters
SSS -8:
#104
Proper motion determination of the optically visible open clusters based on the UCAC4
catalogue
Dias, W. S.B1 ; Monteiro, H.1 ; Caetano, T. C.1,2 ; Lepine, J.2 ; Assafin, M.3
We present a catalog of mean proper motion and membership probability of individual stars for optically
visible open clusters determined using the data from the UCAC4 Catalogue in a homogeneous way. The
mean proper motion of the cluster and the membership probabilities of the stars in the region of each cluster were determined by applying the statistical method of Uribe & Brieva (1994) in a modified fashion. In
this study, we applied a new technique based on the Cross-Entropy global optimization procedure to fit the
observed distribution of proper motions with two overlapping normal bivariate frequency functions, inclusively considering the individual proper motion’s errors. For 724 clusters, this is the first determination of
proper motion and for all we present results with a much larger number of identified astrometric member
stars.
B
1
2
3
[email protected]
IFQ, UNIFEI
IAG, USP
OV, UFRJ
298
Posters
Stars & Stellar Systems
SSS -8:
#105
An psf-fitting pipeline for VVV-ESO: The star cluster Pismis 24
R. A. DiasB1
This work presents a DAOPHOT-based pipeline to perform PSF-fitting pho-tometry of “VISTA Variables in
the Via Láctea” (VVV) ESO Public Survey data.The main feature of the pipeline is to avoid user interaction
keeping photometric accuracy and deepth, in fact it reached accurate photometry for the faintest stars (J,
H, K) and reliable photometry to stars more than one magnitude fainter than the detectable in other techniques. Although getting less accurate data for the brightest stars, the pipeline proved to be the most appropriated approach, since we aim to work with young open clusters, where the pre-main sequence is of major
relevance. Moreover, we can apply 2MASS/VVV matching to replace the VVV’s saturated stars.
B
1
[email protected]
Universidade Federal do Rio Grande do Sul - UFRGS
299
Stars & Stellar Systems
Posters
SSS -8:
#106
Proper motions of pre-main sequence stars
B1
Ferreira, A. C. S.
; Teixeira, R.1 ; Ducourant, C.2 ; Galli, P. A. B.1 ; Le Campion, J. F.2 ; Fidêncio, M.1
The kinematic study of young stars is an important tool to discuss the early stages of star formation. In this
context, proper motions allow us to detect moving group structures of young stars to which they belong.
Individual distances to moving group members can be inferred from proper motion and radial velocity data
using the convergent point strategy. The main objective of this work is to determine proper motions of premain sequence stars in nearby star-forming regions. This work represents an improvement of an existing
database by including more pre-main sequence and refining the astrometry for stars with poor proper motion information in the literature. We calculate the stellar proper motions from observations performed with
the CCD meridian circles located at the Abrahão de Moraes Observatory (Valinhos, SP) and the Bordeaux
Observatory, and also use data from the literature. Here we discuss the accuracy of our results and compare
with published astrometric catalogs.
B
1
2
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, Universidade de São Paulo, Brasil
Observatoire de Bordeaux, France
300
Posters
Stars & Stellar Systems
SSS -8:
#107
The nature of X-ray sources associated to young clusters around Sh2-296
Gregorio-Hetem, J.B1 ; Fernandes, B.1,2 ; Montmerle, T.2
Aiming to unravel the star formation activity in the Canis Major R1 (CMaR1) star-forming Galactic region,
we have studied the young (< 5 Myr) clusters associated to the arc-shaped ionized nebula Sh2-296. Based on
our X-ray data complemented by optical and near-IR data, we discovered, near to GU CMa, a stellar cluster
that is older by at least a few Myr than the previously known cluster, around Z CMa, where star formation
is still very active. We suggest that the CMa R1 region has undergone at least two distinct star formation
episodes. Multi-object optical spectroscopy of our X-ray sources nearby Z CMa and GU CMa has been performed with Gemini telescopes to confirm the existence of a mixed population from both older and younger
clusters around the edge of Sh2-296. In the present work we show the results obtained for the stellar clusters located to the East of Z CMa, where we acquired spectra for optical counterparts candidates of 45 X-ray
sources. Spectral-type determination was based on comparison with standard spectra library for late-type
stars and fitting the continuum and TiO bands. Most of our sample is low-mass young stars, having K7 to
M0 spectral types. Typical features of young stars were inspected to confirm the nature of the sample that is
mainly classified as T Tauri stars (TTs), since their spectra show the Li I (670,8 nm) line, one of the indicators
of youth. The equivalent width of H↵ measured at 10% of the total flux was used to separate Classical TTs
(CTTs) from weak-line TTs (WTTs). Among 51 optical counterparts candidates, 38 are young stars: 24% of
them are classified as CTTs and 76% are WTTs or post-TTs. One object is classified as Herbig Be star and 9
are emission-line stars, which nature remains to be revealed. The few number of CTTs among our sample is
consistent with the mixing of populations that we discovered previously. However the present results correspond to a small fraction (⇠15%) of the entire sample of X-ray sources we have detected with XMM-Newton
around Sh2-296. In order to have a more representative set of spectra, additional GMOS observations have
been performed. Another ongoing project (see Santos-Silva et al.) is dedicated to study the relation of the
X-ray properties of our sample compared to the optical spectral classification obtained in the present work.
B
1
2
[email protected]
Universidade de São Paulo, IAG
Institut d’Astrophysique de Paris
301
Stars & Stellar Systems
Posters
SSS -8:
#108
Stellar parameters and metallicity in Orion Association F and G stars
Rafael Fraga GuerçoB1
The chemical abundance distribution in the young associations of the Milky Way are important in understanding the chemical evolution of the Galaxy and how it formed and evolved. In particular, the chemical
abundances of young stars in association are important to define the present day abundance and address
cosmic scatter.
B
1
[email protected]
Observatório Nacional
302
Posters
Stars & Stellar Systems
SSS -8:
#109
Using MASSCLEAN to Describe Stellar Clusters Found in the Vista Variables in the Via
Lactea (VVV) Survey
Bogdan Popescu1 ; M. M. HansonB1 ; J. Borissova2 ; R. Kurtev2 ; V. D. Ivanov3 ; M. Catelan4 ; S. S. Larsen5 ; D. Minniti4 ;
P. Lucas6
The important parameters of age, mass and distance of resolved or partially resolved stellar clusters are
most accurately determined by using color-magnitude diagrams (CMD). However, when the main sequence
turnoff is not available or clearly identifiable, large errors in all parameters result when using simple isochrone
fitting, particularly when observations are limited to near-infrared bands. We used the MASSCLEAN package
to perform 5 million Monte Carlo simulations of stochastically sampled stellar clusters in order to generate
CMD templates for a variety of cluster masses and ages and which mimic the observational photometric
errors. This results in the creation of tens of thousands of n-dimensional stellar density maps (templates) in
numerous color planes as a function of age and mass. We use these MASSCLEAN CMD templates to refine
and sharpen traditional isochrone fitting to analyze the newly discovered stellar clusters/cluster candidates
from the Vista Variables in the Via Lactea (VVV) Survey. Our MASSCLEAN templates are also being used to
design and optimize search algorithms for stellar clusters in broad-band surveys.
B
1
2
3
4
5
6
[email protected]
University of Cincinnati, USA
Universidad de Valparaiso, Chile
ESO, Santiago, Chile
Pontificia Universidad Catolica, Santiago, Chile
Radboud Universiteit Nijmegen, The Netherlands
University of Hertfordshire, UK
303
Stars & Stellar Systems
Posters
SSS -8:
#110
NIP of Stars: early results and new eclipsing binaries
B1
Jaque Arancibia, M.
; Barba, R. H.2 ; Morrell, N.3 ; Roman Lopes, A.2 ; Torres Robledo, S.2 ; Gunthardt, G.4 ; Soto, M.5 ;
Ferrero, G.6 ; Arias, J.2 ; Gamen, R. 7 ; Fernadez Lajus, E.7
We have performed a near-infrared photometric monitoring of 39 galactic youngstar clusters and star-forming
regions, known as NIP of Stars, between the years 2009–2011, using the Swope telescope at Las Campanas
Observatory (Chile) and the RetroCam camera, in H- and Y-bands. This monitoring program is complementary to the Vista Variables in the Vı́a Láctea (VVV), as the brightest sources observed in NIP of Stars are saturated in VVV. The objective of this campaign is to perform a census of photometric variability of such clusters
and star-forming regions, with the main goal of discovering massive eclipsing binary stars.In this work, we
present a preliminary analysis of this photometric monitoring program with the discovery of tens of candidates for variable stars, among which include candidates for massive eclipsing binaries. We included also
to the analysis of variability, a small set of images obtained in the Ks with the VISTA telescope in the framework of VVV survey (Minniti et al. 2010). In special, we announce the infrared discovering of four massive
eclipsing binaries in the massive young cluster NGC 3603. The stars have been classified spectroscopically
as O-type stars, and one of them, MTT 58, has a rare star with a spectral type of O2 If*/WN6, as one of its
components. We present a preliminary analysis of the light-curves of these binaries.
B
1
2
3
4
5
6
7
[email protected]
ICATE-CONICET, Argentina
Universidad de La Serena, Chile
Las Campanas Observatory, Chile
Observatorio de Cordoba, Argentina
STScI, USA
FCAGLP, Universidad Nacional de la Plata, Argentina
IALP-CONICET, Argentina
304
Posters
Stars & Stellar Systems
SSS -8:
#111
Mass segregation for the young star clusters
Jincheng Y. U.B1
Mass segregation of the young star cluster is one of the dynamical properties which is an important tool to
investigate the star forming process and dynamical evolution of star clusters. The origin of this mass segregation has been suggested as either “primordial”, that is, it is a result of the star formation process in which
stars form mass segregated from their parent molecular cloud, or dynamical, i.e., resulting from fast dynamical evolution. Recent N-body simulations suggest initially dynamically cool and sub-structured star clusters
can be mass segregated within very short timescale. However, the effects of different initial conditions are
still not well understood. Therefore, we investigate the influence of different initial parameters to further
constrain our theoretical model for young-mass segregated star clusters. In particular, we focus on the correlation between the morphology and the degree of mass segregation of the early evolution of young star
clusters.
B
1
[email protected]
Institute of Astrophysics, Pontificia Universidad Catolica de Chile
305
Stars & Stellar Systems
Posters
SSS -8:
#112
Present-day Mass Function of Four LMC Star Clusters with Multiple Stellar Populations
Luque, E. F.B1 ; Kerber, L. O.1
We determined the present-day mass functions (PDMFs) of four intermediate-age clusters NGC 1751, NGC
1783 NGC 1806 and NGC 1846 in the Large Magellanic Cloud (LMC) based on observations with HST/ACS.
These clusters present a remarkable feature in their colour-magnitude diagrams: an extend Main Sequence
Turn-Off, which is commonly interpreted as a signature of multiple stellar population with differences in
age of about a few Myr. The global PDMFs for all clusters are well fitted by power-laws with exponent similar
to the Salpeter one (
= 1.35) ranging from
= 1.28 ± 0.19 (NGC 1846) to
= 1.62 ± 0.23 (NGC 1783).
Our preliminary radial analysis indicates that all systems present some evidence of mass segregation, but at
different degrees.
B
1
[email protected]
Universidade Estadual de Santa Cruz
306
Posters
Stars & Stellar Systems
SSS -9:
#113
Photometric analisys of Galactic Stellar Clusters in VVV Survey
Mauro, F.B1 ; Moni Bidin, C.2 ; Cohen, R.1 ; Geisler, D.1 ; Villanova, S.1 ; Chené, A.-N.3
We’ll show the results of the photometric analysis of several interesting Galactic star clusters (known, new
and candidate) in the “VISTA Variables in the Via Lactea” (VVV) Survey, one of the six ESO Public Surveys
operating on the new 4-meter Visible and Infrared Survey Telescope for Astronomy (VISTA). VVV is scanning the Milky Way bulge and an adjacent section of the disk, where absorption is high, making difficult the
observations in the visible. The data are obtained with the new automatic VVV-SkZ pipeline photometric
pipeline, that permits to have photometry more accurate and with a wider range of magnitudes respect to
other techniques (generally from Ks=9-10 to 18) to study the parameters of the star clusters.
B
1
2
3
[email protected]
Universidad de Concepcion
Universidad Catolica del Norte
Gemini Observatory
307
Stars & Stellar Systems
Posters
SSS -9:
#114
The local dark matter density
Moni Bidin, C.B1
”Weighting” the Galactic disk by means of the kinematics and spatial distribution of its stars is a classical
method of measuring the gravitational mass enclosed in a given volume. Unfortunately, the huge information required for this measurements has so far limited all the investigations to a one-dimensional approximation within 1 kpc from the Galactic plane. Applying a fully three-dimensional formulation to three
kinematical data sets from the literature, extending up to 4 kpc from the plane, we found a surprising lack of
dark matter at the solar position, at variance with previous measurements and with the expectations of the
most accepted dark matter halo models (Moni Bidin et al. 2012, ApJ, 751, 30). Bovy & Tremaine (2012, ApJ,
756, 89) later defied those results, but we recently demonstrated (Moni Bidin et al. 2013, ApJ, submitted) that
their criticism is not a viable explanation of our puzzling results. In this contribution, we will show our most
recent advances in our ongoing studies, based on both synthetic data and an extended SDSS sample of more
than 13000 stars, aimed to understand the origin of the unexpected lack of dark matter previously found.
B
1
[email protected]
Universidad Catolica del Norte, Antofagasta, Chile
308
Posters
Stars & Stellar Systems
SSS -9:
#115
The Origin and Chemical Evolution of the Exotic Globular Cluster NGC 3201
Muñoz, C.B1 ; Geisler, D.1 ; Villanova, S.1
NGC 3201 is a globular cluster (GC) which shows very peculiar kinematic characteristics including an extreme radial velocity and a highly retrograde orbit, strongly suggesting an extragalactic origin. Our aims are
to study NGC 3201 in the context of multiple populations (MPs), hoping to constrain possible candidates for
the self-enrichment by studying the chemical abundance pattern, as well as adding insight into the origin
of this intriguing cluster. We present a detailed chemical abundance analysis of eight red giant branch stars
using high-resolution spectroscopy. We measured 29 elements and found [Fe/H] = -1.53±0.01; we cannot
rule out a metallicity spread of ⇠0.12 dex, and an ↵-enhancement typical of halo GCs. However, significant
spreads are observed in the abundances of all light elements except for Mg. We confirm the presence of an
extended Na-O anticorrelation. n-capture elements generally are dominated by the r-process, in good agreement with the bulk of Galactic GCs. The total (C+N+O) abundance is slightly supersolar and requires a small
downward correction to the isochrone age, yielding 11.4 Gyr. Kinematically, NGC 3201 appears likely to have
had an extragalactic origin but its chemical evolution is similar to most other, presumably native, Galactic
GCs.
B
1
[email protected]
Universidad de Concepción. Chile.
309
Stars & Stellar Systems
Posters
SSS -9:
#116
Detección de cúmulos abiertos en regiones extensas del cielo usando parámetros
astrométricos
Paı́z, L. G.B1 ; De Biasi, M. S.1,2 ; Orellana, R. B.1,2
Se desarrolló un método no paramétrico para identificar cúmulos abiertos en regiones extensas del cielo
utilizando datos precisos de posición y movimiento propio estelar. Se establecieron dos códigos binarios
a partir del análisis de las funciones empı́ricas de densidad de probabilidad en posición y en movimiento
propio, luego de eliminar la contaminación producida por las estrellas de campo en la región estudiada.
Estos códigos definen para cada estrella un parámetro que indica la pertenencia de la misma a una zona de
sobredensidad espacial y sobredensidad en movimiento propio.
Se probó la validez del método aplicándolo a la región comprendida entre 7h 8m  ↵  7h 28m y -
33 
 -29 , que contiene a los cúmulos abiertos Collinder 140 y Collinder 132. Los datos utilizados
fueron obtenidos del catálogo astrométrico UCAC4 hasta magnitud R=11 para asegurar pequeños errores en
movimientos propios. Se detectaron 6 sobredensidades espaciales, de las cuales un nuevo análisis mostró
que 3 podrı́an ser cúmulos abiertos. Se calcularon las coordenadas medias (¯
↵, ¯), radio r y componentes medias de movimiento propio (µ̄↵ cos ¯, µ̄ ) de los 3 candidatos. Uno de ellos es Collinder140, y sus parámetros
obtenidos (¯
↵, ¯)=(110.8 , -32.0 ); r ⇡ 12’; (µ̄↵ cos ¯, µ̄ )=(-3 mas/año, +3 mas/año) muestran un buen acuerdo
con la literatura consultada (Kharchenko et al. 2005, De Biasi & Orellana 2008). Los otros dos posibles
cúmulos, con estrellas en su mayor parte de magnitud más débil que 10.0, no se encuentran en la literatura. Collinder132 no pudo ser detectado debido a que no tiene suficientes miembros brillantes (Orellana
et al. 2010).
B
1
2
[email protected]
Facultad de Ciencias Astronómicas y Geofı́sicas, UNLP
Instituto de Astrofı́sica de La Plata (CCT La Plata – CONICET)
310
Posters
Stars & Stellar Systems
SSS -9:
#117
Galactic Embedded Clusters with 2MASS infrared photometry
Pavani, D. B.B1 ; De Araújo, P. P.; Bica, E.; Bonatto, C.
Star clusters and associations are born in general embedded within giant molecular clouds (GMCs). Because
of this, during their formation and early evolution they are often only visible at infrared wavelengths, being
heavily obscured by dust. Studies have indicated that less 5% of embedded clusters survive beyond the first
million years to become opens clusters. In this work we employed the Two Micron All Sky Survey (2MASS)
photometry to analyze, for the first time, 10 Galactic embedded clusters. We investigated the nature and
derived fundamental parameters for the clusters by applying a field-star decontamination algorithm developed by our group. The method has been systematically used in our publications and have shown how the
effective it is. As a result, this research will bring new information about the history of formation and evolution of the system of embedded and open clusters and their connection with the properties of the Galactic
disk.
B
1
[email protected]
Department of Astronomy, Institute of Physics, Federal University of Rio Grande do Sul/UFRGS
311
Stars & Stellar Systems
Posters
SSS -9:
#118
Probing accretion on the high-magnetized polar RX J1007.5-2017
Rodrigues, C. V.B1 ; Cieslinski, D.1 ; Ribeiro, T.2 ; Silva, K. M. G.1 ; Baptista, R.3 ; de Oliveira, A. S.4 ; Costa, J. E. R.1 ;
Campbell, R.5
RX J1007.5-2017 is a polar: a compact binary system in which matter flows from a low-mass main-sequence
star to a magnetized white dwarf without the formation of an accretion disk. RX J1007.5-2017 has some
observational peculiarities: conspicuous optical cyclotron harmonics; a very soft X-ray spectrum; and no
polarization in R and I bands. These characteristics may be related to extreme conditions at the accretion
flow: a very strong white-dwarf magnetic field (around 100 MG on surface) and a low accretion rate. To
study the accretion, from the secondary to the white dwarf, we obtained time-resolved spectroscopy using
the Goodman spectrograph at the SOAR telescope in observing runs distributed around the first semester
of 2012. We found the object in different brightness states. In the low state, we gathered data with two
spectral resolutions (219 km/s and 170 km/s). In a brighter state, the spectral resolution was approximately
170km/s. The low (high) spectral resolution data cover the spectral region from 360 to 760 nm (435 to 700
nm). The continuum varies in both states and the cyclotron humps are visible in some orbital phases. The
orbital dependence of the cyclotron emission were modelled using the Cyclops code, which adopts a 3D
representation of the accretion column. In the low state, the secondary spectral features are seen as well as
the Balmer emission lines. The spectra in the bright state show Balmer, HeI, and HeII emission lines. The
Balmer and HeII lines components could be separated: in bright state the lines are broader and have three
components. In the low state, the lines are narrower and two components are distinguished in some phases.
These data were analyzed using Doppler tomography. This enables to study the origin of components and
their changes as a function of the brightness state of the object.
B
1
2
3
4
5
[email protected]
Instituto Nacional de Pesquisas Espaciais, Brazil
Universidade Federal de Sergipe, Brazil
Universidade Federal de Santa Catarina, Brazil
Universidade do Vale do Paraı́ba, Brazil
Humboldt State University, USA
312
Posters
Stars & Stellar Systems
SSS -9:
#119
Discriminating Local Group embedded star clusters from older ones using near-IR
photometric indexes
Santos Jr., J. F. C.B1 ; Dottori, H.2 ; Grosbol, P.3
Several grand-design spiral galaxies show a bimodal distribution of their system of star clusters and star
forming complexes in JHK diagrams. In a comparison with stellar population models, the (J
H) vs (H
Ks) diagram revealed that embedded clusters, still immersed in their parental clouds of gas and dust, have
in general a redder (H
Ks) colour than older clusters, whose gas and dust have already been ejected. This
bimodal behavior is also evident in the CMD MK vs (J
Ks ), where the brightest clusters split into two
sequences separating younger from older clusters. In addition, the reddening-free index Qd = (H
0.884 (J
Ks ) -
H) was shown to correlate with age for the young clusters and thus provided an effective way to
differentiate the embedded clusters from the older ones.
In the present work, the aforementioned photometric indices were explored for star cluster systems in the
Local Group. In particular, we investigate the effectiveness of the Qd index in sorting out clusters of different
ages at their early evolutionary stages.
Surface photometry on 2MASS images was carried out for populous clusters younger than approximately
100 Myr and whose ages are available. The integrated magnitudes and colors extracted from the surface photometry of the most populous clusters/complexes in the Local Group showed the same bimodal distribution
in JHK diagrams as that found for more distant galaxies, suggesting that the phenomenum is universal. In
particular, we confirm the index Qd as a powerful tool to distinguish clusters younger than about 7 Myr from
older clusters.
B
1
2
3
[email protected]
Universidade Federal de Minas Gerais
Universidade Federal do Rio Grande do Sul
European Southern Observatory
313
Stars & Stellar Systems
Posters
SSS -9:
#120
ALS 2883: Analysis of spectroscopic features
Silva, A. R.B1 ; Levenhagen, R. S.1 ; Künzel, R.2 ; Leister, N. V.3
Be stars are by definition objects that show or have shown, at least once in its living time, emission in their
Balmer lines. ALS 2883 is a well-known Be-Pulsar system with all its spectroscopic features in emission,
without any direct signature from its photosphere. This emission is a common hallmark among many Be
stars, and this effect is thought to be due to the presence of a circumstellar environment. Also, the presence
of X-ray emissions in this system is nowadays well established, which is often attributed to the presence
of an orbiting compact object. In this study, we present the observations in the visible range of ALS 2883,
performed at MCT/LNA in April 2011. In order to derive fundamental physical parameters and chemical
abundances of the Be star, we solved the radiative transfer equation.
B
1
2
3
[email protected]
UNIFESP
IF-USP
IAG-USP
314
Posters
Stars & Stellar Systems
SSS -9:
#121
Revisiting TW Hydrae in light of new astrometric data
B1
Teixeira, R.
; Ducourant, C.2 ; Galli, P. A. B.1 ; Le Campion, J. F.2 ; Zuckerman, B.3 ; Krone-Martins, A. G. O.4 ; Chauvin, G.5 ;
Song, I.6
TW Hydrae is a very important and interesting target to study star and planet formation due to its youth and
proximity. Nevertheless, it is remarkable the lack of good observational data making the determination of
individual stellar parameters and the membership status for many association members more difficult.
In our work we have measured the proper motion and trigonometric parallax for 15 possible members
of TWA Hydrae that associated to those astrometric, photometric and spectroscopic data from the literature
allow us to refine and improve the previous description and understanding of this association.
In this work we identify a core moving group of 25 stars using our new and improved convergent point
search method, and then derive the dynamical age of the association by applying a traceback technique. We
compare the dynamical age of the association with the age estimate as derived from theoretical evolutionary
models and discuss the properties of individual stars.
B
1
2
3
4
5
6
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, USP
Observatoire de Bordeaux, Université de Bordeaux, LAB
Department of Physics & Astronomy, UCLA
Departamento de Fı́sica, Fac. Ciências da Universidade de Lisboa
Laboratoire d’Astrophysique, Observatoire de Grenoble
Department of Physics & Astronomy, University of Georgia
315
Stars & Stellar Systems
Posters
SSS -9:
#122
On the sensitivity of extrasolar mass–loss rate ranges: HD 209458b a case study
C. Villarreal D’AngeloB1,2 ; M. Schneiter1,2,3,4 ; A. Costa1,2,3,4 ; P. Velázquez5 ; A. Raga5
We present a 3D hydrodynamic study of the effect that different stellar and planetary wind conditions have
on the calculated Ly↵ absorptions during transit. We concentrate, as a case study, on the known HD 209458b
case. By comparing the numerically obtained Ly↵ absorption with the observations, we find that the planetary mass loss rate does not change dramatically for large changes in stellar wind speeds [400
s
1
1200] km
. Several models with anisotropic evaporation profiles for the planetary escaping atmosphere were car-
ried out, showing that both, the escape through polar regions, resembling the emission associated with reconnection processes, and through the night side, produced by a strong stellar wind that compresses the
planetary atmosphere and inhibits its escape from the day hemisphere, yields larger absorptions than an
isotropic planetary wind.
B
1
2
3
4
5
[email protected]
Instituto de Astronomı́a Teórica y Experimental (IATE), Córdoba, Argentina
Fellow of Consejo Nacional de Investigaciones Cientı́ficas y Técnicas (CONICET), Argentina
Member of the Carrera de Investigador Cientı́fico (CONICET), Argentina
Profesor Faculty of Ciencias Exactas, Fı́sicas y Naturales Universidad Nacional de Córdoba, Argentina
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, DF, México
316
Posters
Stars & Stellar Systems
SSS -9:
#123
Abundances and Kinematics of the Galactic Bulge [VVV]
Zoccali, M.B1
I will present the latest results of a spectroscopic survey of bulge K giants, in 25 fields spread across the
bulge area covered by VVV.
B
1
[email protected]
Instituto de Astrofı́sica, Pontificia Universidad Católica de Chile
317
Stars & Stellar Systems
Posters
SSS -9:
#124
White dwarf-main sequence binaries from SDSS DR8: unveiling the cool white dwarf
population
A. Rebassa-Mansergas1,2 ; C. Agurto-GangasB2 ; M. R. Schreiber2,3 ; B. T. Gansicke4 ; D. Koester5
The spectroscopic catalogue of white dwarf main-sequence (WDMS) binaries from the Sloan Digital Sky Survey (SDSS) is the largest and most homogeneous sample of compact binary stars currently known. However,
because of selection effects, the current sample is strongly biased against systems containing cool white
dwarfs and/or early-type companions, which are predicted to dominate the intrinsic population. In this
study, we present colour selection criteria that combines optical (ugriz DR 8 SDSS) plus infrared (yjhk DR
9 UKIRT Infrared Sky Survey, JHK Two Micron All Sky Survey and/or w1w2 Wide-Field Infrared Survey Explorer) magnitudes to select 3419 photometric candidates of harbouring cool white dwarfs and/or dominant
(M dwarf ) companions. We demonstrate that 84 per cent of our selected candidates are very likely genuine
WDMS binaries, and that the white dwarf effective temperatures and secondary star spectral types of 71 per
cent of our selected sources are expected to be below <
⇠ 10000
15000K, and concentrated at ⇠ M 2
M 3,
respectively. We also present an updated version of the spectroscopic SDSS WDMS binary catalogue, which
incorporates 47 new systems from SDSS DR 8. The bulk of the DR 8 spectroscopy is made up of mainsequence stars and red giants that were targeted as part of the Sloan Extension for Galactic Understanding
and Exploration (SEGUE) Survey, therefore the number of new spectroscopic WDMS binaries in DR 8 is very
small compared to previous SDSS data releases. Despite their low number, DR 8 WDMS binaries are found
to be dominated by systems containing cool white dwarfs and therefore represent an important addition
to the spectroscopic sample. The updated SDSS DR 8 spectroscopic catalogue of WDMS binaries consists
of 2316 systems. We compare our updated catalogue with recently published lists of WDMS binaries and
conclude that it currently represents the largest, most homogeneous and cleanest sample of spectroscopic
WDMS binaries from SDSS.
B
[email protected]
Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, China
2 Departamento de Fı́sica y Astronomı́a, Universidad de Valparaı́so, Avenida Gran Bretaña 1111, Valparaı́so, Chile
3 Millenium Nucleus ‘Protoplanetary Disks in ALMA Early Science,’ Universidad de Valparaı́so, Avenida Gran Bretaña 1111, Valparaı́so,
Chile
4 Department of Physics, University of Warwick, Coventry CV4 7AL, UK
5 Institut für Theoretische Physik und Astrophysik, University of Kiel, D-24098 Kiel, Germany
1
318
Posters
Stars & Stellar Systems
SSS -9:
#125
A Candidate Globular Cluster Behind the Milk Way?
A. Roman-LopesB1 ; R. Barba; D. Minniti; R. Carrasco; P. Lucas
In this contribution we will present the results of a study of a candidate Globular Cluster found in the framework of the VVV survey. The new cluster seems to be very old and is possibly crossing the Galactic plane just
behind the Carina Arm, at an heliocentric distance of 7-8 kpc.
B
1
2
3
4
[email protected]
Universidad de La Serena (Chile)
Pontificia Universidad Catolica (Chile)
Gemini South Observatory (Chile)
University of Hertfordshire - (United Kingdom)
319
320
Star Formation
SF -1:
#126
3D Simulations of the Beehive Proplyd
Feitosa, J. A.B1 ; Vasconcelos, M. J.2 ; Cerqueira, A. H.3
Some star formation regions, like Orion nebula, have stars of different masses, from massive stars, responsible for strong ionizing winds and HII regions, to low-mass stars, which spends a long time in protostellar
phase, frequently associated with protostellar disks and jets. Massive O or B stars emit a great deal of UV
radiation, able to dissociate the hydrogen molecule (FUV radiation, energies between 6-13 eV), to ionize the
atomic hydrogen (EUV radiation, energies greater than 13.6 eV) and heat the gas. Around these stars, a large
and hot (104 K) region is formed, known as HII region. T-Tauri stars inside HII regions produce a type of
young stellar object, a proplyd, described with accuracy in O’Dell et al. (1993). Due to the photoevaporation
of protostellar disks by the UV radiation from massive stars in the vicinity, proplyds exibit a cometary shape
from which we can distinguish a central low-mass star with an accretion disk and, eventually, a protostellar jet, an ionization front, a photodissociation region and, sometimes, a bow shock. Characteristics like the
presence or absence of a bow-shock and the photodissociation region’s size depend on the distance between
the low-mass star and the source of ionizing radiation. The Beehive, a giant proplyd in Orion Nebula, has
atractted attention due to its exotic system of rings coaxial to the HH540 jet’s axis. Bally et al. (2005) suggested
that the rings are perturbations due to the crossing of the ionization front by the jet. In this work, we test this
hypothesis making 3D hydrodynamic numerical simulations over an adaptive grid, using the Yguazú-A code
(Raga et al., 2000), properly adapted for the Beehive conditions. Our results show that the jet causes a perturbation in the ionization front of the proplyd, but is necessary to adjust carefully some parameters of the
jet like its velocity and ejection frequency in order to have the results matching the observations.
B
1
2
3
[email protected]
Universidade Estadual de Santa Cruz
Universidade Estadual de Santa Cruz
Universidade Estadual de Santa Cruz
321
Star Formation
Posters
SF -1:
#127
Study of triggered star formation in a bright-rimmed cloud
Ortega, M. E.1 ; Paron, S.1 ; Giacani, E.B1 ; Petriella, A.1
Bright-rimmed clouds (BRCs) are small and dense molecular clouds located in the periphery of the evolved
HII regions. The illumination of these dark clumps by nearby OB stars might be responsible for triggered collapse and subsequent star formation through the mechanism known as radiation-driven implosion (RDI). In
this work, we present a multiwavelength study of a BRC located in the periphery of an uncataloged Galactic
HII region. From the evaluation of the pressure balance between the ionized gas located at the illuminated
border of the clump and the molecular gas, we analyze the influence the ionization front of the HII region
has had on the stability of the BRC. Finally, the young stellar objects embedded in the BRC are characterized
and the possibility that its formation has been initiated by the expansion of the HII region is discussed.
B
1
[email protected]
Instituto de Astronomia y Fisica del Espacio (CONICET-UBA)
322
Posters
Star Formation
SF -1:
#128
On the association of young star clusters and their parental clouds: a statistical fractal
analysis
Hetem, A.B1 ; Gregorio-Hetem, J.2
We present a study of 21 young star clusters aiming to characterize their association to dense clouds. The
structure of the clouds was evaluated by means of the Q statistical fractal analysis, designed to compare
their geometric structure with the spatial distribution of the cluster members. The sample was selected from
the study by Santos-Silva and Gregorio-Hetem (2012) that evaluated the radial density profile of the stellar
superficial distribution of the young clusters. The fractal dimension and other statistical parameters of most
of the sample indicate that there is a good cloud-cluster correlation, when compared to other works based
on an artificial distribution of points (Lomax et al. 2010). As presented in a previous work (Fernandes et al.
2012), the cluster NGC 6530 is the only object of our sample that presents anomalous statistical behavior.
The fractal analysis shows that this cluster has a centrally concentrated distribution of stars that differs from
the substructures found in the density distribution of the cloud projected in the AV map, suggesting that the
original cloud geometry was changed by the cluster formation.
B
1
2
[email protected]
CECS/UFABC
IAG/USP
323
Star Formation
Posters
SF -1:
#129
Increase of Ionization Fraction of Dusty Proto-Stellar Accretion Disks by Damping of
Alfvén Waves
Jatenco-Pereira, V.B1
The ambient of the cloud that gives rise to the process of star formation is consisted of: turbulence, magnetic field and dust. In general, in the process of star formation there is the formation of an accretion disk
whose material must lose their angular momentum in order to be accreted into the central object. The
magneto-rotational instability (MRI) is probably the mechanism responsible for a magneto-hydrodynamic
(MHD) turbulence that leads to disk accretion. However, this mechanism only exists if the gas in the disk
is sufficiently ionized to be coupled to the magnetic field. Besides the viscous heating mechanism often included in the models by means of the ↵-prescription, in this work we study the damping of Alfvéén waves as
an additional heating source. The waves suffer a damping near the dust-cyclotron frequency, since charged
grains in a magnetized disk are highly coupled to the waves due to cyclotron resonances. We study the transfer of energy from the damping of the waves to the disk and we show that this mechanism can increase the
ionization fraction, making possible the presence of the MRI in a large part of the disk.
B
1
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, Universidade de São Paulo
324
Posters
Star Formation
SF -1:
#130
Modeling the circumstellar environment of AB Aur using the Halpha line
Lima, G. H. R. A.B1 ; Perrault, K.2 ; Benisty, M.2 ; Dougados, C.2
AB Aurigae is the brightest Ae Herbig star in the northern hemisphere and it shows evidence of accretion and
ejection processes in the star, moreover the H↵ line shows a P-Cygni profile which is a common indication
of wind. Its H↵ line is very variable, and most of this variation occurs in its blue-shifted side. One of the
processes that can be used to explain this variation is a disk wind similar to those of the classical T Tauri stars.
AB Aurigae has been observed using spectral interferometry in the optical region, by the VEGA spectrometer
in the CHARA-array, which can resolve details of milliarcseconds in size that in the case of AB Aur represent
sizes smaller than 1 AU. With these resolution, it’s possible to observe the region where the wind is being
ejected. Using a radiative transfer code that already had been used to model the H↵ line profiles in classical
T Tauri stars, and adapting it to model the H↵ line in AB Aur, it will be possible to calculate an intensity map
showing the region where this line is being formed, and then compare it with data from the interferometric
observations. This work will give us a better understanding of the ejection and accretion mechanism that
are responsible for the formation of the H↵ line around AB Aur and in some of the Herbig Ae/Be stars, and
wether a disk wind mechanism can explain or not this line in these objects.
B
1
2
[email protected]
Universidade Federal de Minas Gerais
Institut de Planetologie et d’Astrophysique de Grenoble
325
Star Formation
Posters
SF -1:
#131
Steady-state Accretion Disk Models With Variable Alpha
Magalhaes, E. R. S. O.B1 ; Cerqueira, A. H.1 ; Vasconcelos, M. J.1
Accretion disks around young stellar objects are commonly described by models that use a standard average
viscosity to allow, via differential rotation, a mechanism of dissipation and consequent accretion of mass
and angular momentum transport. In this work we use this same prescription to reproduce the final characteristics of an accretion disk, but we relax the condition of constant viscosity using a variable ↵ parameter, as
suggested in recent studies of a selected sample of YSO’s. We first discuss the behaviour of the solutions of ↵
variable, steady-state, thin accretion disks, in comparison with standard solutions of ↵ non-variable. For the
sample of YSO’s studied, we emphasize that ↵ tends to high values close to the star (inner radius), allowing
best conditions for launching jets as expected from both theoretical and observational results. We also evaluate the consequences of this choice on the determination of the initial mass of planetesimals (Mp ). Although
this calculations could not be directly applied to planetary studies (since we have only the steady-state solutions), we can discuss the relevance of it to promote changes in seed values of the mass of the planetesimals,
since it scales with the superficial density profile. These profiles, as we show, are very sensitivy to the ↵
choice, and then, changes Mp accordingly.
B
1
[email protected]
Universidade Estadual de Santa Cruz
326
Posters
Star Formation
SF -1:
#132
A survey of extended H2 emission toward a sample of massive YSOs
Navarete, F.B1 ; Daminelli, A.1 ; Barbosa, C. L.2 ; Blum, R. D.3
Very few massive stars in early formation stages were clearly identified in the Milky Way and moreover, the
processes of formation of such objects lacks of observational evidences. Two theories predict the formation
of massive stars: i) by merging of low mass stars or ii) by an accretion disk. One of the most proeminent
evidences for the accretion scenario is the presence of bipolar outflows associated to the central sources.
Those structures were found on both intermediate and low- mass young stars, but there are no evidences for
associations with MYSOs. Based on that, a survey was designed to investigate the earliest stages of massive
star formation through the molecular hydrogen transition at 2.12 µm. A sample of ⇠ 300 massive YSO can-
didates was selected from the Red MSX Source survey (Mottram et al., 2011) and the sources were observed
with the IR cameras Spartan (at SOAR, Chile) and WIRCam (at CFHT, Hawaii). Extended H2 emission was
found toward 55% of the sample and 30% of the positive detections (50 sources) have a bipolar morphology,
suggesting collimated outflows. These results support the accretion scenario, since the merging of low mass
stars would not produce jet-like structures.
B
1
2
3
[email protected]
Universidade de São Paulo, Brazil
UNIVAP, Brazil
NOAO
327
Star Formation
Posters
SF -1:
#133
A Spectro-photometric study if the young stellar cluster sigma Orionis.
Pérez A.B1 ; Hernández J.1 ; Calvet N.2 ; Olguin L.3 ; Contreras M.4 ; Briceño C.1 ; Allen L.5 ; Espailat C.6
We performed a spectro-photometric study of the young stellar cluster Sigma Orionis with the purpose of obtain a better characterization for its stellar population. The sigma Orionis cluster is a natural laboratory used
to study the formation and early evolution of stars and protoplanetary disks from its most massive member
to planetary mass objects. This is because it is reasonably near (D<500pc), the reddening toward the cluster
is low (Av⇠0.2) and it is relatively populous. Its age of 3 Myr allows us to perform studies of protoplanetary
disks around stars with different masses when disk dissipation processes have modified substantially the
structure of disks.
Analyzing great amount of data collected from different observatories and instruments we have the capacity to recognize and to characterize members of the cluster in a homogeneous way. With this in mind we
have obtained UBVRI photometry from the OSMOS instrument installed in the 2.4 telescope at the MDM
observatory.
Low resolution spectra come from several spectrographs with similar spectroscopic coverage and resolution (HECTOSPEC-MMTO, FAST-FLWO, OSU-CCDS-MDMO, B&C-San Pedro Martir, B&C-Cananea). This
data was processed with specialized programs such as IRAF and the SpTClass code (Spectral CLASSificator)
to obtain spectral types and the basic analysis of spectral features normally present in young stars (e.g. Halpha in emission and LiI 6707 in absorption). With these results we have recognized members of the sigma
Orionis cluster and obtained stellar parameter such as effective temperature, visual extinction and luminosity.
In addition, radial velocity were derived from HECTOCHELLE data (obtained at MMTO) using the IRAF
package rvsao with cross-correlates each spectrum with a set of templates. The radial velocity distribution
for members of the cluster can be described by a Gaussian centered at 30.8 km/s with a sigma of 1.7 km/s.
This result is in agreement with previous work.
B
1
2
3
4
5
6
[email protected]
Centro de Investigaciones de Astronomı́a (CIDA), Mérida, Venezuela
Department of Astronomy, University of Michigan, Ann Arbor, MI 48109, US
U. de Sonora, Mexico
UNAM-Ensenada, Mexico
NOAO, USA
Harvard-Smithsonian Center for Astrophysics.
328
Posters
Star Formation
SF -1:
#134
Time-series JHK Photometry of Stars in the center of Cygnus OB2
Roquette, J. M. T.B1 ; Vaz, L. P. V1 ; Guimarães, M. M.2
Cygnus OB2 is an OB association located in the direction of the Local Spiral Arm, harbouring some of the
most massive and luminous stars in the Galaxy. Studying its high mass population, we learned that it is a
rich star forming region, located behind a dust cloud which is responsible for the high extinction measured
in that area of the sky (10 – 20 MV ). Its estimated age of 3Myr makes it an appropriate target for studying
young stars.
We performed a photometric variability survey in this region using near-infrared filters (JHK), with the
Wide Field Camera (WFCAM) of the United Kingdom Infrared Telescope (UKIRT), during 112 nights, unevenly spaced in a period of 217 days. A total area of 520.96 ⇥ 520.96 was covered with Cygnus OB2 in its center.
We present provisional results concerning rotational periods for stars stars within its central region (a
sub-area of 130 .65 ⇥ 130 .65 ).
B
[email protected]
Universidade Federal de Minas Gerais (UFMG)
2 Universidade Federal de São João Del Rei (UFSJ)
1
329
Star Formation
Posters
SF -2:
#135
Infrared study of new star clusters associated to dusty globules
Soto King, P.B1 ; Barba, R. H.1 ; Roman Lopes, A.1 ; Firpo, V.1 ; Soto, M.2 ; Minniti, D.3 ; Lucas, P.4
We present results from a study of a sample of small star clusters associated to dusty globules and brightrimmed clouds that have been observed with VISTA telescope in the framework of the ESO/Chile public
infrared survey Vista Variables in the Vı́a Láctea (VVV). Also, we included in the analysis data collected by
Spitzer Space Telescope and Wide-field Infrared Survey Explorer. In this short communication, we present
the infrared properties of the clusters derived from the color-color and color-magnitude diagrams. We identify and classify young stellar objects (YSOs) through the infrared spectral energy distribution combining the
available mid-infrared photometry and the PSF analysis performed on VVV images. Also, we derive the ratio
between Class I to Class II YSO source candidates in each globule. The sample of selected dusty globules
and bright rimmed globules are extracted from the new list of VVV clusters discovered at Universidad de La
Serena. These dusty globules are simple laboratories to study the star formation relatively free of the influence of large star-forming regions and clusters, and they are in contrast compared with those bright rimmed
globules, which are influenced by the action of nearby O and B massive stars.
B
1
2
3
4
[email protected]
Universidad de La Serena
Space Telescope Science Institute
Pontificia Universidad Catolica de Chile
University of Hertfordshire
330
Posters
Star Formation
SF -2:
#136
The inner disks of classical T Tauri stars in NGC 2264
B1
Sousa, A. P.
; McGinnis, P. T.1 ; Alencar, S. H. P.1 ; Bouvier, J.2 ; Texeira, P.3 ; Stauffer, J.4 ; CSI2264 Team
NGC 2264 is a young (⇠ 3 Myr) stellar cluster that was observed twice by the CoRoT satellite, for 23 days in
2008 and 40 days in 2011. Simultaneouslys with the 2011 CoRoT observations, a multiwavelength campaign
was organized that included 30 days of Spitzer observations at 3.6 and 4.5 microns, 3.5 days of Chandra data,
VLT FLAMES spectroscopy and U band photometry from Megacam (CFHT). We obtained simultaneous high
precision light curves in the optical and near IR for more than 500 cluster members, about 150 of which are
classical T Tauri stars. As shown in the first CoRoT campaign, a fraction of the accreting systems exhibit
optical light curves with deep minima that vary substantially in width and depth in a rotational timescale.
These light curves are interpreted as being due to an inner disk warp that eclipses the star as the system
rotates, as observed in AA Tau, a well studied CTTS seen at high inclination. This warp is thought to be
created by the star-disk interaction mediated by a stellar magnetic field inclined with respect to the stellar
rotation axis. The observed variability indicates that the star-disk interaction is dynamic and the occulting
material is inhomogeneous and located close to the co-rotation radius of the star-disk system. We present
the photometric and spectroscopic analysis of the AA Tau-like CTTSs observed in NGC 2264. Initial light
curve model results indicate that an inner disk warp located near the co-rotation radius can indeed explain
the observed variability and that, if the variability is attributed to extinction alone, the properties of the dust
in the inner disk are substantially different from the ISM.
B
1
2
3
4
[email protected]
Universidade Federal de Minas Gerais - UFMG
Institut de Planétologie et d’Astrophysique de Grenoble - IPAG
Institut für Astrophysik Universität Wien
Spitzer Science Center - Caltech
331
Star Formation
Posters
SF -2:
#137
Finding proto-spectroscopic binaries: Precise multi-epoch radial velocities of 7
protostars in Ophiuchus
Viana Almeida, P.B1,2,3,4 ; Melo, C.2 ; Santos, N. C.1,3 ; Figueira, P.1 ; Sterzik, M.2 ; Gameiro, J. F.1,3 ; Alencar, S.4
Stars in the solar neighborhood are mostly found in multiple systems. While the existence of stellar companions at visual distances can be easily explained as a normal outcome of the star formation process itself,
it is still unclear how spectroscopic companions are actually formed. If they are a by-product of the initial
fragmentation of molecular clouds, or resultant from dynamical evolution within pristine multiple systems
is still an open question in star formation. To uncover a young spectroscopic binary would be therefore an
invaluable clue for understanding the mechanisms and the time scales involved in their formation. Aiming
at finding such young spectroscopic companions, we present a near-IR high resolution (R > 50000) multiepoch radial velocity survey of 7 young stellar objects in the star forming region rho Ophiuchus. The radial
velocities of each source were derived using a two-dimensional cross-correlation function designed to deliver the radial velocity of the target relative to the zero-point established by the earth’s atmosphere. We
found that the spectra of the protostars in our sample agree reasonably well with predicted stellar photospheric profiles indicating that the radial velocities uncovered are of stellar nature. Three of the targets analyzed give us string evidence that the first proto-spectroscopic binaries might have been found. We present
preliminary orbital solutions for two of the targets based on six epochs of observations. If these binaries are
further confirmed, it will bring an important piece into the (binary) star-formation puzzle, namely, that multiplicity at sub-AU scale starts (or not) at birth. Our preliminary binary fraction of 71% (when merging our
results with those of previous studies) is also in line with the notion that multiplicity is very high at young
ages and therefore it might be a product of star-formation.
B
1
2
3
4
[email protected]
Centro de Astrofı́sica, Universidade do Porto
ESO/Chile
Departamento Fı́sica e Astronomia, Faculdade de Ciências da Universidade do Porto
ICEX, Universidade Federal de Minas Gerais
332
Posters
Star Formation
SF -2:
#138
Chromospheric and Coronal Activity in Stars Before the Main Sequence
Alexander, N. C.B1 ; Giovanni, P. E.1
In the study of stellar activity spectroscopy plays an important role behind this variability are discussed in
important lines of the spectra taken by powerful tools with which today account. In this work we make a
spectroscopic analysis which makes fluxes calculation to find indicators such as chromospheric and coronal
RHK indicator of CAII in 3920 Å, and two lines in the infrared triplet (IRT) at 6500 Å CAII activity chromospheric; for use coronal activity normalized soft X-ray bolometric fluxes; These indicators correlate with
rotation Nr (Rossby number) and age for a sample of stars from different open clusters of different ages as:
BMW (11-12 Myr), UCL (14Myr), LCC (16Myr), THA (30M yr) and different spectral types F, G and K the basic
idea of this work is to verify that these indicators of activity decay with time and are closely related to stellar
rotation (Marsden et al 2009). For chromospheric analysis using spectral subtraction technique (Montes et
al. 1995) and also a compilation of sample data for the ROSAT X-ray fluxes in total the number of stars that
will be analyzed is 42 and 4 reference stars. All spectra are taken from the database ESO (European Southern
Observatory with the FEROS instrument (The Fiber-fed Extended Range Optical Spectrograph) whose resolution of 48000 and a hedge between 3200-9000 Å allows us to perform more detailed analysis of the lines of
interest.
B
1
[email protected]
Universidad Nacional de Colombia
333
Star Formation
Posters
SF -2:
#139
Emission-line stars in the star-formation region NGC 1850
Garrido, H. E.B1,2 ; Martayan, C.1 ; Mennickent, R. E.2 ; Aguayo, G.2 ; Baade, D.3
We studied the properties of the stellar populations in a field 11 x 8’ around the center of the OB association
NGC 1850, based on the analysis of slitless spectroscopic data obtained with the ESO Wide Field Imager, 63
emission-line stars and one Double period variable star located in and around the LMC clusters NGC 1850
and NGC 1855 have been identified.
Most of the emission-line stars are located in the vicinity of the young double cluster NGC 1850. Among
them, In addition to pre-main sequence stars and giant stars, new candidate B0-B5 Be stars were also found.
The photometry and lightcurves are also used to obtain additional physical parameters of those stars such as
their evolutionary status/age. Combining all these observations suggests that the NGC 1850 star-formation
history has followed different episodes due to the dynamical interaction between clusters, photo-ionization,
and compression of the associated H II region, leading to ”recent” star formation bursts. The OB association
NGC 1850 is found in the border of the Supergiant shell LMC 6 and their local background zone. We conjecture that the expansion of the SGS LMC 6 could play a role in the current star formation in the zone. Our
analysis of the stars in the field indicate a possible mass and spatial segregation with the evolution/age of
the clusters and stellar populations.
B
[email protected]
European Organisation for Astronomical Research in the Southern Hemisphere, Alonso de Cordoba 3107, Vitacura, Casilla 19001,
Santiago 19, Chile
2 Universidad de Concepción, Departamento de Astronomı́a, Casilla 160-C, Concepción, Chile
3 European Organisation for Astronomical Research in the Southern Hemisphere, Headquartes, Garching bei Munchen, Germany
1
334
Posters
Star Formation
SF -2:
#140
Magnetic Fields dispersion and YSO properties on nearby Bok globules
Magalhães, V. S.B1 ; Rodrigues, C. V.2 ; Pereyra A.2 ; Racca G. A.2 ; Vilas-Boas, J. W. S 2
We conducted an observational study of the relation between magnetic field properties and star formation
in Bok globules. We used polarimetry to map the interstellar magnetic field direction in twenty (20) sky regions containing Bok globules. The maps created were used to estimate the dispersion of the magnetic field
direction in each region fitting the polarization angle histogram to a gaussian curve. In addition to the Gaussian dispersion, we propose a new quantity to estimate the magnetic field organization that does not rely
on any function fitting. We selected all the red sources in the WISE Point Source Catalog in 15’ x 15’ regions
centered on the Bok Globules. We then constructed spectral energy distributions (SEDs) using publicly available data (2MASS, AKARI, GLIMPSE, WISE). To verify whether the sources are pre main-sequence objects we
compared the SEDs to young stellar objects (YSOs) models available online (Robitaille et al. 2007). This also
yielded estimates of mass, age, inclination of the found YSOs. With this information at hand we classified
the regions as star forming or not. Statistical tests show no clear difference in the magnetic field dispersions
of the sub-samples of globules with and without star formation. We also discuss some trends as a function
of the YSOs properties.
B
1
2
[email protected]
Currently Unaffiliated
Divisão de Astrofı́sica, Instituto Nacional de Pesquisas Espaciais
335
Star Formation
Posters
SF -2:
#141
Star formation at the edge of the Universe
Matos, S.B1 ; Best, P.1 ; Sobral, D.2
The most fundamental observational properties that need to be determined to obtain a comprehensive understanding of the physical processes of galaxy formation and evolution are the cosmic star formation history of the Universe and the volume-averaged star formation rate as a function of epoch. Previous studies
have made considerable progress in recent years, but even so their measurements are affected by significant scatter and uncertainties due to the use of different star-formation indicators, worsened by small area
sampling and the effects of cosmic variance. We aim at overcoming these issues by using wide-field, sensitive un-biased surveys of star-forming galaxies at a range of redshifts across the peak epoch of cosmic
star-formation. We present the first robust sample of star-forming galaxies at high redshifts (Lyman-emitter
at z > 7) is obtained from a large area (12 deg2 ) extragalactic survey within the epoch of reionisation and
places strong constraints on the bright end of the Lyman-luminosity function.
B
1
2
[email protected]
Royal Observatory of Edinburgh, University of Edinburgh
Leiden Observatory, University of Leiden
336
Posters
Star Formation
SF -2:
#142
Rotation and activity of Post T Tauri Stars
Pinzón, G.B1
We present the main results of a study of rotation and chromospheric activity of 33 young post T Tauri low
mass stars of the southern hemisphere with spectral types G-K belonging to the stellar associations: TWA
Hya ( 10Myr), BPMG ( Myr), Upper Centaurus Lupus (UCL, 20Myr), Lower Centarus Crux (LCC, 23Myr) and
Tucana - Horologium (THA, 30Myr). Using both, UBVRI photometry and FEROS optical spectra we found
that the rotation - activity relation shows prominent differences with those observed in main sequence stars
indicating that young low mass stars generate their magnetic fields in a different way. Theoretical predictions
using a time-dependent stellar spin evolution model were also done and confirm that such kind of spin up
is a consequence of the end of the disks at the begining of the post T Tauri stage.
B
1
[email protected]
Observatorio Astronómico, Facultad de Ciencias, Universidad Nacional de Colombia
337
338
ISM
ISM -1:
#143
New Avenues for Measuring Magnetized Turbulence in the Multiphase Interstellar
Medium
Burkhart, B.B1 ; Lazarian, A.1
The current paradigm of the ISM and Solar Wind is that it is turbulent with turbulence affecting many important processes. For the ISM this includes star formation, cosmic ray acceleration, and the evolution of
structure in the diffuse ISM. This makes it important to study interstellar and interplanetary turbulence using the strengths of numerical studies combined with observational studies. I shall discuss progress that has
been made in the development of new techniques for comparing observational data with numerical magnetohydrodynamic (MHD) simulations. In particular I will discuss the robustness of measuring the sonic
Mach number from molecular line observations, which is an important tool for investigating the dynamics
of Giant Molecular Clouds. I will also discuss how one can obtain estimations of the magnetic field in interstellar clouds using statistical methods rather than the traditional time consuming methods such as Zeeman
spliting. These new techniques fit into the broader scope of providing avenues for studying MHD turbulence
across different ISM phases.
B
1
[email protected]
University of Wisconsin Madison
339
ISM
Posters
ISM -1:
#144
3D Modelling of the Bipolar Planetary Nebula NGC 2346
Carneiro, C. M.B1 ; Gonçalves, D. R.1
Planetary nebulae (PNe) represent the final stages of evolution of low- and intermediate-mass stars, when
the matter ejected from the star forms bright ionized shells. Most of the PNe are not spherically symmetric
(about 70% are of ellipticals and bipolars and 20% have round morphologies) possibly because of the binarity
of the central star. Photoionization codes intent to reproduce the interactions of the central star’s radiation
with the nebular gas, in order to obtain information of both, gas and central star. So, it is possible to determine the electron temperature and density, the ionization stage of the elements, as well their ionic and total
chemical abundances. Concerning the star, its effective temperature and luminosity can also be deduced.
The chemical abundances of PNe provide an important tool to study the chemical evolution of galaxies.
These abundances are mostly derived using the ionization correction factors empirical method, which are
strongly uncertain, since they were derived using 1D photoionization codes, which assume spherical symmetry to all PNe. There is only one 3D model of a bipolar planetary nebula (NGC 6302) in the literature.
We are developing the modelling of the bipolar PN NGC 2346, which has a single-lined spectroscopic binary
central star. From the best model we obtained, so far, this is a low electron density nebula (⇠ 300 cm
3
),
with typical PNe electron temperature (10,000 K to 14,000 K) and a hot central star (10 K), for which lumi5
nosity (therefore, distance) is not yet well constrained. The agreement of our best fitting model with the
intense optical emission-lines is of 96%, though the dimensions used in this model might be slightly underestimated. Improved models including dust and a more accurate central star ionizing radiation (T. Rauch’s
stellar atmosphere results) will be presented, as well as the fitting to others (than optical) spectral regions
whose observational constraints are available.
B
1
[email protected]
Observatório do Valongo, Universidade Federal do Rio de Janeiro
340
Posters
ISM
ISM -1:
#145
G126.1–0.8–14: A molecular shell related to Sh2-187
Cichowolski, S.B1 ; Pineault, S.2 ; Gamen, R.3,4 ; Ortega, M. E.1 ; Arnal, E. M.3,5 ; Suad, L. A.5
In this work we present a multi-wavelength study of a region where a well defined molecular shell (G 126.1–
0.8–14) is observed. G 126.1–0.8–14 is located in the Orion arm, at a distance of about 1 kpc. Based on
CGPS HI and CO data we analyze the atomic and molecular gas related to the structure and estimate its
main physical properties. From the radio continuum and infrared data we analyze whether the emission
associated with G 126.1–0.8–14 has a thermal origin. On the other hand, to disentangle the possible origin for
the shell, and given the lack of catalogued O-type stars in the area, we observed with GEMINI the spectrum
of four OB stars (Reed 2003, AJ, 125, 2531) located in projection inside the shell, to get their accurate spectral
types and distances. The HII region Sh2-187 is located onto the densest part of this molecular shell. It
is known that this ionized region is small (⇠ 9’) and young (⇠ 2 ⇥ 105 yr), and shows signs of recent star
formation activity in its surroundings. A search for young stellar object candidates (cYSO) was made using
different infrared point source catalogs (IRAS, MSX, WISE, and 2MASS). Besides the sources present near
Sh2-187, many others are found spread out onto the shell. Based on all the available data, we discuss the
possible origin of G 126.1–0.8–14 as well as its role in the formation of a new generation of stars.
B
1
2
3
4
5
[email protected]
Instituto de Astronomı́a y Fı́sica del Espacio (IAFE)
Université Laval
Facultad de Ciencias Astronómicas y Geofı́sicas
Instituto de Astrofı́sica de La Plata
Instituto Argentino de Radioastronomı́a (IAR)
341
ISM
Posters
ISM -1:
#146
Deep infrared extinction maps of the Fourth Galactic Quadrant based on VVV and
GLIMPSE surveys
Firpo, V.B1 ; Soto, M.2 ; Barba, R. H.1 ; Roman Lopes, A.1 ; Minniti, D.3 ; Lucas, P.4
The ESO/Chile public infrared survey VISTA Variables in the Vı́a Láctea (VVV) is changing our view of the
inner Galactic disk and Bulge. The VVV survey have observed 220 deg2 of the Galactic plane in 152 tiles,
in five infrared bands. Based on these tiles of the Galactic disk, we have created a merged catalogue in
three bands (J, H and Ks) using the photometric catalogues produced by the CASU pipeline. This merged
catalogue with 136 millions sources was used to produce deeper source-count maps, and then again crossmatched with GLIMPSE (Spitzer Space Telescope) catalogue, to get a combined VVV-GLIMPSE catalogue,
with 12.4 ⇥ 106 stars. In this presentation, we report the development of a VVV+GLIMPSE extinction map
for the Fourth Quadrant of the Galactic disk based on the Rayleigh-Jeans Color Excess method (Majewsky
et al.). For a wide range of spectral types, the combination of NIR and MIR photometry allows to sample
the Rayleigh-Jeans part of the spectral energy distribution, where the intrinsic color of stars falls in a narrow
range. Thus, a simple color equation can be used to derive the extincion per star in the Ks -band, AK . These
new maps are in agreement with recent works, and represent a significant improvement over the current
situation because of, thanks to the VVV protometry, we have obtained deep extinction maps with a spatial
resolution of 1 arcmin.
B
1
2
3
4
[email protected]
Universidad de La Serena, Chile
Space Telescope Science Institute, USA
Pontifica Universidad Catolica, Chile
University of Hertfordshire, UK
342
Posters
ISM
ISM -1:
#147
A bolha infravermelha N10
Gama, D.B1 ; Lepine, J.1 ; Wu, Y.2 ; Yuan, J.2
A formação de estrelas massivas ainda não está totalmente compreendida. Bolhas infravermelhas podem
prover indı́cios sobre as condições fı́sicas da interação entre regiões HII e ventos de estrelas massivas. O objeto N10 é uma bolha infravermelha, detectada através do GLIMPSE, um levantamento realizado entre 3.6
e 8.0 µm. A inspeção visual revelou anéis que podem representar bolhas tridimensionais. Autores sugerem
que essas bolhas são primeiramente formadas por estrelas quentes em regiões de formação estelar. Bolhas
formadas dinamicamente precisam de uma estrela, ou aglomerado, com emissão UV suficiente para excitar
caracretı́sticas de PAHs nas bandas IRAC 5.8 e 8.0 µm. Também foi analisada a emissão em 24 µm, que é
resultado da emissão da poeira quente. Já a emissão em 8 µm é dominada por caracterı́sticas de PAHs excitados por radiação proveniente das PDRs. No caso de N10, propõe-se que o excesso na banda 4.5 µm do
IRAC indicaria um outflow - assinatura de estágios primários de formação de estrelas massivas. Sugere-se
que a bolha seja soprada por uma região HII central. Esse objeto foi alvo de observações realizadas no PMO,
que possui uma antena de 13.7 metros, situada na cidade de Nanjing, China. As transições moleculares observadas foram 12 CO (1-0), 13 CO (1-0) e C18 O (1-0), nas frequências de 115, 110 e 109 GHz, respectivamente.
A investigação da bolha N10 pode revelar detalhes acerca da atividade de formação estelar devida a processos sequenciais nessa região, assim como fornecer informações a respeito do status do material molecular
associado com a bolha. Os próximos passos serão utilizar rotinas adequadas para obter parâmetros observados na região, para a componente principal, segunda e terceira componentes, tanto para a emissão em 12 CO
quanto em 13 CO. Por meio dos parâmetros observados, podemos estimar a distância do objeto e comparar
o valor encontrado com valores da literatura calculados por outros métodos. A bolha N10 apresenta clumps,
dos quais podemos obter parâmetros fı́sicos através dos parâmetros observados. A discussão seguirá acerca
da distribuição do gás na região e seu ambiente molecular. Também pretendemos discutir sobre o estágio
evolutivo dos clumps, comparando a localização destes com a posição de fontes rádio, maser de metanol
e estrelas tipo O ionizantes. Para avaliar a situação de formação estelar em N10, também realizamos um
levantamento dos YSOs.
B
1
2
[email protected]
Departamento de Astronomia do IAG/USP, São Paulo, Brasil
Department of Astronomy, Peking University, Beijing, China
343
ISM
Posters
ISM -1:
#148
The magnetic field and dust properties in the direction of the dark cloud CG12
Hickel, G. R.B1
The dark cloud CG12 is situated about 200 pc above the Galactic Plane and 600 pc away from us. It has a very
denser double core with 100 M (Avmax ⇠ 20 mag.). The cloud is under a radiative shock that triggers low
mass star formation (⇠50 TTauri stars) with a high efficiency (⇠15 to 35%). In this work, I present a linear
polarization (BVRI filters) in the CG12 direction. I analyzed the relationship between the polarization degree
and extinction, and the dependency on the polarization degree with the wavelength along the cloud. The
geometry and magnetic field strength were evaluated using the dispersion of the vectors of linear polarization.
B
1
[email protected]
UNIFEI
344
Posters
ISM
ISM -1:
#149
High dispersion spectra and kinematic line profiles of NGC3918 and NGC6302
Lago, P. J. A.B1 ; Costa, R. D. D.1
Planetary Nebulae have rich optical spectra, formed by recombination and collisional excitation lines. The
use of these lines allows the derivation of several physical parameters such as density, electron temperature,
ionization degree and the kinematic profile. These nebulae have typical expansion velocities between 20 and
40 km/s. Using high dispersion, long slit spectroscopy obtained with the Coudé spectrograph at Pico dos
Dias Observatory (MCT/LNA) in Brazil, we derived the kinematic profile from forbidden lines for different
angular positions along the slit for two nebulae, NGC3918 and NGC6302. The second one shows a velocity
profile that grows linearly with the distance to center. Using the velocity diagrams from this work and data
from the literature, it was possible to calculate the distance of NGC6302, estimated in 805pc with an error
of 143pc, in a good agreement with other results from the literature. For NGC3918, the same diagrams were
used to estimate its kinematic age, assuming expansion with uniform velocity; the result was 3111 years for
the external shell. Hereafter we intend to use the kinematic profiles to model these planetary nebulae with
the SHAPE code, and apply this technique for a large number of southern planetary nebulae. (FAPESP, CNPq)
B
1
[email protected]
Universidade de São Paulo, Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas
345
ISM
Posters
ISM -1:
#150
3MdB: Mexican million models database
Christophe MorissetB1 ; Gloria Delgado-Inglada1
We present the actual status of the 3MdB (Mexican Million Models dataBase). This database of photoionization models obtained with Cloudy are managed by MySQL from python using the pyCloudy package. The
genetic method used to converge models on a set of observations is also presented, with prelimininary results on physical properties and abundances determination.
B
1
[email protected]
Instituto de Astronomia, UNAM, Mexico
346
Posters
ISM
ISM -1:
#151
Structure of Bubbles in the South-East region of the Large Magellanic Cloud
Oddone, M. A.B1 ; Ambrocio-Cruz, P.2 ; LeCoarer, E.3 ; Goldes, G. V.4
In this work we report the kinematical results of the structure located in the South-East region of the Large
Magellanic Cloud, the Super Giant Shell LMC9. The observations have been carried out in the frame of an
H↵ survey of the Magellanic Clouds and the Milky Way, carried out at ESO with a 36cm diameter telescope,
equipped with a focal reducer, a scanning Fabry-Perot interferometer and a photon counting camera. The
Supergiant Shell LMC9 is composed of four giant shell DEM164 and DEM165, DEM208, DEM221, and several
HII region being the most notorious DEM202, DEM206 and DEM207. Morfologically, two of the complexes
present structure of bubble-type, one of them DEM208 of oval shape of (200 x 180) pc with another structure
in its interior near circular of 100 pc, meanwhile the HII regions DEM202, DEM206, DEM207 semble to form
a unique structure conected by curve filaments of eliptical shape with a mayor axis of 250 pc. Other two
complexes DEM164 and DEM165 seen ensemble seems to form an extended filament (400 pc) with an “S”
shape. The complex DEM221, is the most irregular with (400 x 300) pc size, resembling by its filamentary
and irregular appearance to the 30 Dorado nebula. By means of energy balance we determine the characteristics parameters of these structures (superfical brightness, electronic density, emission measure, mass,
luminosity, ambient density, age), that would allow us to distinguish which is the origin (stellar wind, supernova explosion or other mechanism) of the differents bubbles that compose the Super Giant Shell LMC9. In
this way we will try to discern if the studied objects have kinematically some identity as an ensemble, or if
they are relatively aisolated objects over the diffuse general background to which they belonged. The same
were investigated with the intention of stablishing its general kinematic and morphological characteristics
and in addition analyzing its possible association to a large structure aiming above all to contribute to the
elaboration of a detailled global kinematics image of the LMC.
B
1
2
3
4
[email protected]
Observatorio Astronómico de la Universidad Nacional de Córdoba, Laprida 854, X500BGR, Córdoba, Argentina
Instituto de Ciencias Básicas e Ingenierı́a, Universidad Autónoma del Estado de Hidalgo, México
Laboratorio de Astrofı́sica de la Universidad Joseph Fourier, Grenoble, Francia
Facultad de Matemática, Astronomı́a y Fı́sica, Córdoba, Argentina.
347
ISM
Posters
ISM -2:
#152
A new distance scale of planetary nebulae
Ortiz, R.B1
A new distance scale of planetary nebulae is proposed, based on two main quantities: the flux density (or
magnitude) at 8µm and the nebular apparent size. These quantities are used to calculate the specific intensity of the radiation I8µm , which decreases as the nebula evolves. PNe situated in the Large Magellanic
Cloud (LMC) with 8µm photometry obtained by Spitzer and diameter calculated from HST observations are
used as calibrators. After calibration, distances of PNe in the LMC were recalculated, and showed a 1-sigma
spread of 10 kpc (20%). Eventually, the method was applied to a sample of 88 Galactic PNe observed during the Spitzer survey. These results showed an agreement within 0.2 dex with the distances determined by
Stanghellini et al. (2008), which is another method calibrated with PNe in the LMC. The main advantage of
the present distance scale is the fact that it is nearly “extinction free”, which makes it especially suited for
PNe severely affected by interstellar extinction, such as the Galactic disc and bulge.
B
1
[email protected]
Escola de Artes, Ciências e Humanidades da USP
348
Posters
ISM
ISM -2:
#153
Spectroscopic studies of two supernova remnants in the Large Magellanic Cloud
Pauletti, D.B1 ; Copetti, M. V. F.1
Some characteristics of supernova remnants can be quite different in different objects, depending on their
formation mechanisms, evolution stages and the properties of the local interstellar medium. Even within a
single remnant, some physical properties can vary considerably. However, a great part of the spectroscopic
works published about supernova remnants are based on integrated data (distant objects) or on data obtained from special positions (near objects). Spatially resolved observation covering the whole remnant may
be essential to get a better knowledge of these objects.
This work presents a study of two supernova remnants belonging to the Large Magellanic Cloud, N49
and N11L, based on the spectroscopic mapping of their physical properties. Long slit spectroscopy was
used to collect data from a grid of different positions covering the whole nebula by positioning the slit on
different and equally spaced declinations. The data were obtained with the 4.1 m SOAR telescope (Southern
Astrophysical Research Telescope), in Chile. The spectral coverage was about 3500-8000 Å.
For each object, about 50 emission lines were measured on the spectra of each object, allowing to build
maps of many interesting line intensity ratios. The maps of electron density and temperature were obtained
using the [S II] 6717/ 6731 and [O III] ( 5007+ 4959)/ 4363 line ratio sensors, respectively. N49 presents a
strong density gradient with the density varying from 600 cm
3
at the North-West to more than 3000 cm
3
at the South-East. The electron temperature distribution shows a rough spherical symmetry with the higher
values found at the centre. In N211L the electron density varies from less than 100 cm
3
to about 400 cm
3
,
with the higher values found on the bright filaments. These maps were used to build a picture of the structure
of these two supernova remnants.
B
1
[email protected]
Universidade Federal de Santa Maria
349
ISM
Posters
ISM -2:
#154
Densities, temperatures, pressures, and abundances derived from O II recombination
lines in H II regions and their implications
Peimbert, M.B1 ; Peimbert, A.1
Based on high quality observations of multiplet V1 of O II and the NLTE atomic computations of O II we study
the density and temperature of a sample of H II regions. We find that the signature for oxygen rich clumps of
high density and low temperature is absent in all objects of our sample. These results imply that the proper
abundances are those derived from recombination lines. We discuss the possible mechanisms responsible
for the abundance discrepancy problem in H II regions.
B
1
[email protected]
Instituto de Astronomia, Universidad Nacional Autonoma de Mexico
350
Posters
ISM
ISM -2:
#155
Multiwavelength study of the young stellar cluster [DBS2003]156
Marcio C. PinheiroB1 ; Roberto P. Ortiz2 ; Zulema Abraham3 ; Marcus V. F. Copetti4
The Norma section of the Milky Way is especially interesting because it crosses three spiral arms: SagittariusCarina, Scutum-Crux and the Norma arm itself. We present a study of the [DBS2003] 156 stellar cluster in
Norma, associated with several radio sources characteristic of the presence of massive stars, such as continuum, H109↵ and methanol. The cluster was observed in the J, H and Ks bands at 1.300 resolution and
limiting magnitudes comparable to the 2MASS survey. Potential massive stars were chosen among the infrared sources detected in the survey according to colour criteria, and subsequent spectroscopy of these
candidates was performed with the OSIRIS spectrograph attached to the SOAR 4.1-m telescope. As a result,
four stars with spectral types earlier than B1 were found, which are capable of maintaining the ionization
of this nebula. The distance of this cluster, calculated by the spectrophotometric parallax technique, is
3.30 ± 0.55 kpc, in full agreement with the distance of the neighbouring [DBS2003] 157 cluster, previously
determined as 3.29 ± 0.59 kpc. A comparison between Spitzer mid-infrared counterparts of the infrared
sources detected in this survey with mid-infrared colours generated by theoretical models allows a crude
estimation of the density of the accreting envelope around the young stellar objects in the cluster, between
log ⇢(g cm
3
)=
14.0 ⇠
13.35. [DBS2003] 156 and 157 are mutually associated and are members of the
Scutum-Crux spiral arm.
B
1
2
3
4
[email protected]
Universidade Federal da Fronteira Sul
Escola de Artes, Ciências e Humanidades, Universidade de São Paulo
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, Universidade de São Paulo
Laboratório de Análise Numérica e Astrofı́sica, Universidade Federal de Santa Maria
351
ISM
Posters
ISM -2:
#156
Spatial variations of physical and chemical properties of the planetary nebulae
NGC 6302 and NGC 2440
Rauber, A. B.B1 ; Copetti, M. V. F.2 ; Krabbe, A. C.3
In this work, we present an analysis of the physical and chemical conditions of the planetary nebulae NGC
6302 and NGC 2440 through spatially resolved spectroscopy. Multiple parallel long-slit spectra were obtained
with the Goodman spectrograph attached to the 4.1 m SOAR telescope, allowing the construction of maps
and spatial profiles. Densities were estimated from the [S II] and [Ar IV] sensors. For NGC 6302, a peaked
distribution was found, with the densest area at the circumstellar region, reaching Ne ⇡ 40000 cm
decreasing to Ne  1000 cm
3
at the bipolar lobes. Knots with Ne ⇡ 2000
3000 cm
3
3
and
and an inner outflow
region were observed. The density maps of NGC 2440 show complex characteristics. In the central structures densities reach more than 4500 cm
3
. Structures with 1000 < Ne < 1500 cm
3
are associated with the
bipolar lobes at P.A. ⇡ 60 and P.A. ⇡ 85 . Electron temperatures were estimated from the [N II] and [O III]
sensors and homogeneous distributions were found for these objects. The average values of the maps were
12304 K and 17380 K, respectively, for Te (N II) and Te (O III) in NGC 6302. In NGC 2440, these same values
were 11273 K and 13722 K, respectively. Small temperature flutuations on the plane of the sky were obtained,
with t2s  0.012 for NGC 6302 and t2s  0.017 for NGC 2440. Abundances of N+ , O+ , S+ , O2+ , Ne2+ , Ar3+ relative to H+ were determined from collisionally excited lines, and relative abundances of He+ and He2+ from
recombination lines. These ionic abundance maps show significant spatial variations. The highest dispersions relative to the mean ionic abundances were observed for the N+ /H+ , O+ /H+ and S+ /H+ maps, going
from 50% to 70%. Regions with marginal evidence of overabundance of N were found. No sign of shock
excitation is found for any of the structures of these objects.
B
1
2
3
[email protected]
Universidade Federal de Santa Maria
Universidade Federal de Santa Maria
Universidade do Vale do Paraı́ba
352
Posters
ISM
ISM -2:
#157
The Magnetic Field Structure in the Musca Dark Cloud
Ribeiro, N. L.B1 ; Magalhães, A. M.1 ; Pereyra, A.2
Our goal is the study of the magnetic field (MF) structure of a pre-collapse structure of the interstellar
medium - the Musca Dark Cloud (MDC), a nearby (200-250 pc), large (0.25 x 3 ) filamentary cloud. A description of the MF, together with knowledge on turbulence and gravitational forces, is key to understanding
the evolution of interstellar clouds.
We have obtained linear polarization measurements in the H band (1.65 µm) with the Brazilian’s 60 cm
and 160 cm telescopes located at the OPD observatory. By combining these with our earlier optical observations (Pereyra & Magalhaes 2004), we were able to probe regions denser than what was possible in the
optical.
Our studies in the optical band showed that the cloud is surrounded by a MF which is well aligned with
the projected small axis of the cloud. Our H-band data show in general the same tendency in the inner parts
of the MDC. The comparison between the V and H bands allow us to conclude that the same type of grains
are polarizing the light throughout the cloud at least up to Av ⇠ 8-9, and that these are the same as those in
the general ISM. Utilizing the dispersion of the polarization vectors, we estimated the MF intensity (0.02-0.16
mG) across the cloud. We compared the magnetic and gravitational energies and concluded that Musca is a
subcritical cloud. From the structure function of the polarization at the H band, we obtain 0.21-0.29 pc for
the range of correlation lengths of the MF in the cloud.
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1
2
[email protected]
IAG - University of São Paulo
IAC - Spain
353
ISM
Posters
ISM -2:
#158
The Magnetic Field Structure of the Interstellar Medium From the observations Open
Clusters
Rubinho, M. S.B1 ; Magalhães, A. M.1
This project aims to study the magnetic field of the Galactic diffuse interstellar medium (ISM) using imaging
polarimetry data towards Open Clusters. These data are from the Interstellar Polarization Survey, that has
been carried out in the LNA. The interstellar polarization toward members of these clusters will show the
alignment of the grains in the ISM and hence trace the magnetic field. The study of our clusters at various
distances from the Sun will thus probe the magnetic field at various angular scales. The polarization of stars
was obtained by imaging polarimetry technique in the V filter, with Tel. 60cm IAG at LNA. For data analysis
we used the pccdpack package, developed by our group for the IRAF environment. We show the current
state of data reduction, and present results for various directions along the Galactic Plane for clusters with
distances ranging between 484pc and 2200pc.
B
1
[email protected]
IAG-USP
354
Posters
ISM
ISM -2:
#159
Carbon abundances in the disk of NGC300 from faint CII recombination lines
Toribio-San Cipriano, L.B1 ; Esteban, C.1 ; Garcı́a-Rojas, J.1
We present the results of deep echelle spectrophotometry for a sample of HII regions in the Scd galaxy
NGC300 obtained with the Ultraviolet and Visual Echelle Spectrograph (UVES) at the VLT. The main aim
of this study is to detect and measure faint OII and CII recombination lines (RLs) along the disk of NGC300.
In fact, we have successfully derived the C++/H+ ratio from the CII 4267A RL along the disk of NGC300. This
is a very important result because, although Carbon (C) is the second most abundant heavy-element in the
Universe, there are only few C abundance determinations for extragalactic HII regions, and they are mainly
derived from UV collisionally excited lines (CELs), which intensity is very much affected by interstellar reddening. A well known, and striking, result is that the abundances obtained from the CII 4267A RL are larger
than that obtained from the UV CIII] 1907+09 CELs. C abundance determinations from RLs in extragalactic
HII regions, combined with chemical evolution models, may help to clarify which kind of lines -CELs or RLsgive the true abundances. If RLs give the ”real” abundances, it would imply that the actual content of heavy
elements in the Universe is two times higher than usually assumed.
B
1
[email protected]
Instituto de Astrofisica de Canarias, Spain
355
ISM
Posters
ISM -2:
#160
The Discrepant Kinematics of ORLs and CELs in NGC 7009 as a Function of Ionization
Structure
Richer, M. G.1 ; Georgiev, L.2 ; Arrieta, A.3 ; Torres-Peimbert, S.B2
We present spatially- and velocity-resolved echelle spectroscopy for NGC 7009 obtained with the UVES spectrograph at the European Southern Observatory’s Very Large Telescope. Our objective is to analyze the kinematics of emission lines excited by recombination and collisions with electrons to determine whether similarities or differences could be useful in elucidating the well-known abundance discrepancy derived from
them. We construct position-velocity maps for recombination, fluorescence, charge transfer, and collisionallyexcited lines. We find a plasma component emitting in the C II, N II, O II, and Ne II recombination lines
whose kinematics are discrepant: They are incompatible with the ionization structure derived from all other
evidence and the kinematics derived from all of these lines are unexpectedly very similar. We find direct evidence for a recombination contribution to [N II] 5755. Once taken into account, the electron temperatures
from [N II], [O III], and [Ne III] agree at a given position and velocity. The electron densities derived from [O
II] and [Ar IV] are consistent with direct imaging and the distribution of hydrogen emission. The kinematics
of the C II, N II, O II, and Ne II lines does not coincide with the kinematics of the [O III] and [Ne III] forbidden emission, indicating that there is an additional plasma component to the recombination emission that
arises from a different volume from that giving rise to the forbidden emission from the parent ions within
NGC 7009. Thus, the chemical abundances derived from either type of line are correct only for the plasma
component from which they arise. Apart from [N II] 5755, we find no anomaly with the forbidden lines
usually used to determine chemical abundances in ionized nebulae, so the abundances derived from them
should be reliable for the medium from which they arise.
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1
2
3
[email protected]
Instituto de Astronomı́a - Ensenada, Universidad Nacional Autónoma de México
Instituto de Astronomı́a, Universidad Nacional Autónoma de México
Universidad Iberoamericana, México
356
Galaxies
GAL -1:
#161
Stellar feedback from black-hole high-mass X-ray binaries in galaxy formation models
Artale, M. C.B1,2 ; Tissera, P. B.1,2 ; Pellizza L. J.1,2
In recent years, many works have suggested the role of black-hole high-mass X-ray binaries (BH-HMXB) as
potential sources of heating and reonization of the intergalactic medium, due to the large mean free path of
X-ray photons. Furthermore, because of the suggested increase of their production rate and X-ray luminosity with decreasing metallicity, BH-HMXBs could be relevant to explain the thermal and ionization history of
the Universe at its early stages. However, observations indicate that a meaningful amount of the energy released by these sources could be deposited in the local interstellar medium, suggesting that BH-HMXB could
modify star forming regions on the host galaxy. In this work, we study the kinetic BH-HMXB feedback using
hydrodynamical cosmological simulations of galaxy formation which also include SNe feedback. We present
preliminary results on how the energy input from BH-HMXBs could change the star formation history of the
galaxies over time.
B
1
2
[email protected]
Instituto de Astronomı́a y Fı́sica del Espacio, C.C. 67 Suc. 28, C1428ZAA Ciudad de Buenos Aires, Argentina
Consejo Nacional de Investigaciones Cientı́ficas y Técnicas, Rivadavia 1917, C1033AAJ Ciudad de Buenos Aires, Argentina
357
Galaxies
Posters
GAL -1:
#162
Properties of galaxies in fossil and non-fossil groups from the maxBCG sample
Luiz AzanhaB1 ; Robert N. Proctor1 ; Claudia Mendes de Oliveira1
Fossil groups are defined as X-ray bright galaxy groups or clusters with a brightest cluster galaxy that is at
least 2 magnitudes brighter than any other galaxy within half the virial radius of the system. The current
consensus is that these systems form when dynamical friction causes any massive galaxies in the central regions of the system to spiral inwards and merge with the central galaxy. These systems are therefore expected
to be relatively isolated and old. The goal of this project is to build a new sample of fossil group galaxies for
statistical studies, from the maxBCG catalogue, as well as a control sample of normal cluster/groups and
compare distributions of virial radii, radial velocities and luminosity functions of galaxies in fossil and nonfossil systems. A sample of 2000 groups of the maxBCG sample was analyzed and we found 30 candidate
fossil groups. Our results on the comparison of the properties of fossil and non-fossil groups will be presented.
B
1
[email protected]
IAG-USP
358
Posters
Galaxies
GAL -1:
#163
Dinâmica da Formação de Galáxias com Anel Polar
Dino Beghetto JuniorB1 ; Irapuan Rodrigues de Oliveira Filho2 ; Maximilliano Faúndez-Abans3
Apresentamos aqui a fase inicial de um projeto que pretende investigar em detalhe a dinâmica da formação
das Galáxias com Anel Polar (PRG, do inglês: ”Polar Ring Galaxy”). Uma PRG é formada por uma galáxia
hospedeira do tipo precoce, lenticular ou elı́ptica, rodeada por um anel de gás e estrelas orbitando um plano
quase perpendicular com relação ao plano principal da galáxia hospedeira. Discutiremos as principais propriedades dinâmicas desses objetos através de um levantamento bibliográfico com ênfase nos mecanismos
propostos para explicar a sua formação. Existem dois principais cenários propostos para a formação de
PRGs (BORNAUD; COMBES, 2003): (i) fusão de duas galáxias espirais com discos ortogonais em colisão
frontal, e (ii) acréscimo de gás, de uma galáxia doadora para a galáxia hospedeira, durante um encontro
próximo. Além desses, também existe o cenário de formação de anel polar por acréscimo de gás dos filamentos cósmicos (MACCIÒ et al, 2005). Em qualquer desses cenários teóricos, os anéis polares se formam
por interações entre galáxias ou de uma galáxia com o seu entorno cósmico. Uma evidência disso é que os
anéis polares observados parecem sempre mais jovens do que as respectivas galáxias hospedeiras. O objetivo primário deste trabalho é construir uma base de dados de simulações numéricas, buscando evidenciar
que parâmetros estão mais diretamente envolvidos na formação das PRGs. Além disso, uma vez construı́da
a base de dados, ela será uma ferramenta importante no estudo da dinâmica de PRGs observadas. Depois do
processo de formação de uma PRG, quando o anel já se estabilizou, perde-se muito da ”memória” do processo de formação, tornando difı́cil o estudo da sua história dinâmica. Os resultados observacionais obtidos
para uma PRG em estudo poderão ser confrontados com as simulações da base de dados e, a partir da análise
do ”best match”, sua dinâmica atual e pregressa poderão ser investigadas.
B
1
2
3
[email protected]
IPD-UNIVAP
IPD-UNIVAP
LNA/MCTI
359
Galaxies
Posters
GAL -1:
#164
Metal-Poor Active Galactic Nuclei
Bicalho, I. C.B1 ; Telles, E.1 ; Thuan, T.2 ; Izotov, Y3
Active galaxies are considered to be metal-rich, with metallicity ranging from solar to slightly supersolar.
This is due to the fact that the active galaxy nuclei are usually found in massive galaxies. We present the
results based on analysis of data from Gemini Near Infrared Integral Field Spectrograph (NIFS+ALTAIR) of
the metal-poor HII galaxy SDSS J1047+0739. We aim to test the hypothesis of the presence of an AGN in low
metallicity dwarf galaxies that show strong permitted emission lines with extended wings, which is atypical
for HII regions. We also use unconventional methods such as PCA tomography due to the benefits that
it provides to data analysis. We are studying the kinematics of the nuclear region and the regions of star
formation surrounding it, mostly through the Paschen-alpha and [He] lines. After a throughout discussion
on the question of effective resolution of our observations provided by the point spread function (PSF) with
the adaptive optics system, we find that the broad line emission comes only from the unresolved central
region, consistent with the presence of an AGN in this metal-poor galaxy.
B
1
2
3
[email protected]
Observatório Nacional, Rio de Janeiro-RJ
Astronomy Department, University of Virginia, Charlottesville - Virginia - USA
Main Astronomical Observatory, Ukrainian National Academy of Sciences, Kyiv - Ukraine
360
Posters
Galaxies
GAL -1:
#165
Analysis of the Velocity Data of Cluster A562
Calderón Espinoza, D.B1 ; Gomez, P.2
We present a study of the velocity of the cluster of galaxies Abell 562 to understand the physical mechanism
that produces the bending in the radio jets of the central elliptical galaxy of the cluster. We test if the ram
pressure between the central radio source and the intracluster medium (ICM) is a good explanation for the
phenomenom. To do this we used Gemini North Multi-Object Spectroscopy data from the members of the
cluster, finding that the central galaxy does not have enough relative velocity for bending its jets by ram
pressure. But from the analysis of the velocity distribution we found a substructure that suggests a merger.
B
1
2
[email protected]
Departamento de Astronomı́a y Astrofı́sica, Pontificia Universidad Católica de Chile
Gemini South Observatory
361
Galaxies
Posters
GAL -1:
#166
Internal kinematics of HII galaxies
Carvalho, M.B1 ; Plana, H.1
H II galaxies are dwarf galaxies caracterized by high stellar formation rate with spectrum dominated by
strong emission lines, superimposed on a weak stellar continuum. The study of internal kinematics of these
objects may be realized using the observed emission lines. Based on these lines we obtained monochromatic intensity, velocity dispersion and radial velocity maps. We have studied the internal kinematics of two
H II galaxies: UM 461 and CTS 1020, observed with the Gemini South telescope using the GMOS instrument
equiped with an IFU. We aim to investigate the origin of the line-broadening observed on emission lines
from the use of kinematics diagnostic diagrams: I vs , I vs V , e V vs . The analysis of these diagrams
was based on the Cometary Stirring Model that allows us to identify, for example, the presence of expanding
shells and stellar winds. We found that radial velocity and velocity dispersion maps, for each galaxy, show a
different kinematical pattern, although both are H II galaxies. CTS 1020 shows a velocity gradient consistent
with a rotating disc with a velocity amplitude of ⇠50 km s
1
. On the other hand UM 461 does not exhibit
a typical pattern of a rotating system, despite of the observed velocity gradient in both emission nuclei, but
shows signs of an expanding shell. We also perform, for both galaxies, a PCA analysis of the data cubes,
showing much weaker lines such as: He I 4471Å, [OI]6300Åand [SIII]6312Å.
B
1
[email protected]
Laboratorio de Astrofisica Teorica e Observacional - UESC - Ilheus - Brazil
362
Posters
Galaxies
GAL -1:
#167
Dynamical Analyses of z= 0.3, 0.5 Galaxy Clusters from the SOAR Gravitational Arcs
Survey
Cibirka, N.B1 ; Cypriano, E.1 ; Caminha, G.2 ; Makler, M.2
We have performed dynamical analyses of galaxy clusters using optical spectroscopic data. These clusters
belong to the SOAR Gravitational Arcs Survey (SOGRAS) (Furlanetto et al. 2013) and are among the richest
structures in SDSS stripe 82 with redshifts around z= 0.3 or z= 0.5. For three of those clusters, all with
strong lensing features, we carried out individual analysis using Gemini/GMOS data (⇠ 25 velocities per
cluster). We obtained masses in the range of 3
8 1014 M and signs of substructure in one of them. For the
whole SOGRAS sample (47 clusters) we used SDSS spectroscopic data. Given the low number of velocities
per clusters, we stacked the data per redshift and/or richness. Our results indicate that the richest half of
the clusters, independently of the redshift, tend to be ⇠ 2.5 times more massive than the poorest half. Also
we have found that the z= 0.3 and the z= 0.5 clusters have overall masses statistically consistent with each
other: 6.3(+3.9
B
1
2
2.1) and 8.6(+5.2
1.6)1014 M respectively.
[email protected]
Instituto de Astronomia, geofı́sica e Ciências Atmosféricas, Universidade de São Paulo
Centro Brasileiro de Pesquisas Fı́sicas
363
Galaxies
Posters
GAL -1:
#168
The connection between the origins of globular clusters and the evolution of their host
galaxy
Arianna CortesiB1 ; Ana Chies-Santos1 ; Steven Bamford1 ; Michael Merrifield1 ; Aaron Romanowsky2 ; Jacob Arnold2 ;
Vincenzo Pota3 ; Duncan Forbes3 ; Lodovico Coccato4 ; J. P. Brodie2 ; Chris Usher3 ; Jay Strader5 ; Caroline Foster6
Star kinematics is directly connected to the evolution history of their host galaxy. However, to recover the
correct kinematics, it is necessary to assign each tracer of the starlight to the galaxy component it belongs to:
the disk (thin or thick) or the spheroid. Performing a multi-band decomposition of infrared images of our test
case NGC 3115, using MegaMorph, and planetary nebulae (PNe) as tracers of the overall stellar populations,
we recovered the velocity and velocity dispersion of the thick disk and of the spheroid. We then studied
the globular cluster (GC) population in NGC 3115. Given a GC position and velocity we can estimate its
probability of belonging to the disk, to the spheroid and in general to the system. We find that most GCs
are consistent of being drawn from the light weighted velocity distribution of NGC 3115 stars. Nearly half of
the GCs belong to the disk and half to the spheroid, but we don’t find any trend between their colour (B-R)
or calcium triplet abundances with their kinematics. In this talk I will explore different formation scenarios
that can accommodate our findings.
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1
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3
4
5
6
[email protected]
School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD
University of California Observatories, Santa Cruz, CA 95064, USA
Centre for Astrophysics & Supercomputing, Swinburne University, Hawthorn VIC 3122, Australia
European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching, Germany
Michigan State University
Australian Astronomical Observatory
364
Posters
Galaxies
GAL -1:
#169
The evolution of galaxies between 0.05 < z < 0.8
Costa-Duarte, M. V.B1 ; Stasinska, G.2 ; Sodré Jr., L.1 ; Cid Fernandes R.3
Nowadays several surveys provide databases of thousands of galaxy spectra which allow us to investigate the
evolution of galaxies. From the shape of the continuum and from the information encoded in the absorption and emission lines it is possible to recover the star formation history of the galaxies and investigate their
nuclear activity. We have studied the evolution of galaxies in the redshift range 0.05< z <0.85 by considering
spectra from the SDSS/DR7 and zCOSMOS surveys. We distinguished the galaxies by their stellar masses
and for each mass and metallicity bin we obtained a representative spectrum by stacking all the relevant
spectra. We see regular trends in the galaxy properties both as a function of stellar mass and of redshift.
Using spectral synthesis we confirm the downsizing scenario, i.e., more massive galaxies present older stellar populations. Massive galaxies are already formed at z=0.85 while less massive objects are still forming
stars. We also study the evolution of galaxies of different masses in emission-line diagnostic diagrams, and
discuss how the proportion of galaxies of different types, i.e. pure star-forming, galaxies containing an active
nucleus, and retired galaxies (galaxies that have stopped forming stars), evolve as a function of redshift for
different mass bins.
B
1
2
3
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas - Universidade de São Paulo
Observatoire de Paris - Meudon - Paris - France
Universidade Federal de Santa Catarina
365
Galaxies
Posters
GAL -2:
#170
Galaxy Concentration Index in Low X-ray Luminosity Galaxy Clusters
Cuevas, H.B1 ; Nilo Castellón, J. L.1 ; Alonso, M. V.2
Using a sample of 10 low x-ray luminosity galaxy clusters (Nilo Castellón et al. 2013B), we studied the properties of 146 galaxies classified as members in a redshift range of 0.185 < z < 0.701.
Following Concelice et al. 2000, we define the galaxy concentration index (C), as the ratio of two circular
radii which contain 80 and 20 percent of the total Petrosian flux. Mainly, we observed an increment of C
for early-type and lenticular galaxies at redshifts lower than 0.3, that can be related to the presence of giant
galaxies in these low redshift clusters (C > 4). Contrary to these results, for late-type galaxies we found
smaller C values for the lower redshift clusters.
These results could be associated to the morphological evolution of galaxies, as proposed by different
authors (Poggianti et al. 2009, Dressler et al. 2009) for rich clusters.
B
1
2
[email protected]
Departamento de Fı́sica, Universidad de La Serena, Chile
Instituto de Astronomı́a Teórica y Experimental (IATE-CONICET), Argentina
366
Posters
Galaxies
GAL -2:
#171
Probing the Spacial Distribution of the Near-infrared Stellar Population in Starburst
Galaxies
N. Z. DamettoB1 ; R. Riffel1 ; M. G. Pastoriza1 ; A. Rodrı́guez-Ardila2 ; E. A. Carvalho2,3 ; J. A. Hernandez-Jimenez1
In this work we employ Infrared Telescope Facility SpeX near-infrared (0.8-2.4µm) spectroscopy to investigate the spatial variation of the stellar populations in four well known Starburst galaxies: NGC 34, NGC 1614,
NGC 3310 and NGC 7714. We use the STARLIGHT code, updated with the synthetic simple stellar populations models computed by Maraston 2005, to fit combinations of stellar population models of various ages
and metallicities. Our main results are that the near-infrared light in the central region of the galaxies is
dominated by intermediate-age stars (1 ⇥ 108  t  2 ⇥ 109 Gyr), summing ⇠50% of the light, followed
by a secundary contribution of a young stellar population. The only case ruling this out is NGC 34, which
shows a predomiance of a young age (t  50 ⇥ 106 Myr) stellar population in the nuclear surroundings
(60 %). We found evidence of a circumnuclear star formation ring-like structure with young/intermediate-
age star in NGC 1614, in agreement with previous studies. Also, we conclude that the metallicity traces the
intermediate-age stellar population in almost all the sources. The reddening is nearly constant along the
whole galaxy in the four cases.
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1
2
3
[email protected]
Departamento de Astronomia, Universidade Federal do Rio Grande do Sul
Laboratório Nacional de Astrofı́sica/MCTI
Campus São João Del Rei, Instituto Federal do Sudeste de Minas
367
Galaxies
Posters
GAL -2:
#172
The relation between the spectral synthesis of galaxies in the visible region and their
UV emission
Dantas, M. L.B1 ; Sodré Jr., L.1
Under the STARLIGHT Project, almost a million spectra, which were extracted from the Sloan Digital Sky
Survey (SDSS), were analyzed with the empirical spectral synthesis approach described by Cid Fernandes et
al. (2005). The spectral synthesis involves the fitting of the optical spectrum of a certain galaxy based on the
spectral database of Bruzual & Charlot (2003). It also considers the reddening caused by dust and the spectral
line widening caused by the Doppler Effect due to the motion of the stars within the galaxy. Since the model
that best fits the optical region can also be extended to the ultraviolet, we have compared our predictions
to the UV photometry of the same galaxies mesured by the GALEX satellite, studying the systematics and
nature of the differences. The main motivation of this study is to obtain realistic spectral models from the
UV to the optical region for the study of high redshift galaxies.
B
1
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas da USP
368
Posters
Galaxies
GAL -2:
#173
Resolving galaxies in time and space: Applying STARLIGHT to CALIFA data cubes
de Amorim, A. L.B1 ; Cid Fernandes, R.1,2 ; Perez, E.2 ; Garcia Benito, R.2 ; González Delgado, R. M.2 ; Sanchez, S. F.2, 3 ;
Husemann, B.4 ; Falcon Barroso, J.5,6 ; Sanchez-Blazquez, P.7 ; Walcher C. J.4 ; Mast D.2,3
Fossil record methods based on spectral synthesis techniques have matured over the past decade, and their
application to integrated galaxy spectra fostered substantial advances on the understanding of galaxies and
their evolution. Yet, because of the lack of spatial resolution, these studies are limited to a global view, providing no information about the internal physics of galaxies.Motivated by the CALIFA survey, which is gathering Integral Field Spectroscopy over the full optical extent of 600 galaxies, we have developed an end-to-end
pipeline which: (i) partitions the observed data cube into Voronoi zones in order to, when necessary and taking due account of correlated errors, increase the S/N, (ii) extracts spectra, including propagated errors and
bad-pixel flags, (iii) feeds the spectra into the STARLIGHT spectral synthesis code, (iv) packs the results for
all galaxy zones into a single file, (v) performs a series of post-processing operations, including zone-to-pixel
image reconstruction and unpacking the spectral and stellar population properties into multi-dimensional
time, metallicity, and spatial coordinates.This work provides a description of this whole pipeline and its data
products. These include 3D cubes of the stellar formation history, 2D maps of galaxy properties such as the
v-field, stellar extinction, mean ages and metallicities, mass surface densities, star formation rates on different time scales and normalized in different ways, 1D averages in the temporal and spatial dimensions,
projections of the stellar light and mass growth (x,y,t) cubes onto radius-age diagrams, etc. The results illustrate the richness of the combination of IFS data with spectral synthesis, providing a glimpse of what is to
come from CALIFA and future IFS surveys.
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1
2
3
4
5
6
7
[email protected]
Universidade Federal de Santa Catarina
Instituto de Astrofı́sica de Andalucı́a
Centro Astronómico Hispano Alemán, Calar Alto
Leibniz-Institut für Astrophysik Potsdam
Instituto de Astrofı́sica de Canarias
Universidad de La Laguna, Tenerife
Universidad Autónoma de Madrid
369
Galaxies
Posters
GAL -2:
#174
Detection and modelling of star cluster early phases in grand-design, spiral galaxies
Grosbol, P.1 ; Dottori, H.B2
Deep, near-infrared maps in ZJHK-maps for ten nearby, grand-design, spiral galaxies using HAWK-I at the
ESO Very Large Telescope, allowed to obtain a complete, magnitude-limited list of candidates of star-forming
complexes searching within the K-band maps. The detection of thousands of candidates per galaxy enables
a good statistic treatment of the data. Our analysis indicates that cluster younger than 7 Myr have significant
internal extinction AV =3-7 mg, while for the older ones AV ' 1m .0. The cluster luminosity function is well
fitted by a power law with exponential around 2 and does not show evidence of high luminosity cut-off. The
brightest cluster complexes reach luminosities MK =-15m .5 with estimated masses of 106 M . The CLF in the
arms is also shifted towards brighter MK by at least 0m .4. At the two-armed spiral pattern the star formation
rate is higher by a factor of 2-5 than in the inter-arm regions. The (J-K) vs MK diagram of several galaxies
shows, for the brightest clusters, a clear separation between young clusters that are highly attenuated by dust
and older ones with low extinction. Monte Carlo simulations of cluster populations were performed using
the power-law distribution function g(M, ⌧ ) / M ↵ ⌧ . Integrated colors were computed from Starburst99
models. The derived near-infrared color-magnitude diagrams were compared to those observed for 6 granddesign, spiral galaxies using statistical tests for goodness-of-fit. The color-magnitude distributions indicate a
significant mortality of young, massive clusters with = -1.1±0.3. High initial extinction AV = 8-11 and strong
nebular emission are required to reproduce the bi-modal color distributions of the clusters. An extended star
formation phase of more than 5 Myr is suggested during which the extinction starts to decrease over a period
of 5-10 Myr.
B
1
2
[email protected]
European Southern Observatory, K. Schwarschild Str. 2, Garching b. München
Instituto de Fı́sica, UFRGS, Brazil
370
Posters
Galaxies
GAL -2:
#175
Two-dimensional Stellar Kinematics and Dynamical Models for NGC 4258 and
NGC 1052
Drehmer, D. A.B1 ; Storchi-Bergmann, T.1 ; Ferrari, F.2 ; Riffel, R. A.3
In this work we present a two-dimensional mapping of the stellar kinematics of the inner 300 ⇥300 region of the
galaxies NGC 4258 and NGC 1052, derived from spectroscopic observations with the Near-Infrared Integral
Field Spectrometer (NIFS) at the GEMINI North Telescope. For NGC 4258, the velocity distribution is dominated by a strong velocity dispersion gradient, requiring the presence of a Supermassive Black-Hole (SMBH)
there. Assuming that the distribution function (DF) depends on three integrals of motion, we constructed
a Jeans Anisotropic Model to fit the observed velocity distribution. Our dynamical model assumes that the
galaxy has axial symmetry and uses the Multi-Gaussian Expansion (MGE) method to parametrize the observed surface brightness distribution. The model has three free parameters: the mass of the central SMBH
(M• ), the mass-luminosity ratio (M/L) of the galaxy and the anisotropy in the velocity distribution. Modeling
the kinematics of the galaxy without considering the contribution of the SMBH, we obtain a velocity profile
dominated by rotation. By adding the contribution of a central SMBH, and systematically increasing the
value of its mass, the modeled velocities increase considerably in the central region, passing from a velocity field dominated by rotation to one dominated by velocity dispersion in the innermost region, consistent
with the observations. From the best-fitting model, we obtain the values for the free parameters which best
reproduce the observed kinematics. After testing the reliability of our model on NGC 4258 (which has already
a well determined value for M• ), we apply the same procedure to model the stellar kinematics of NGC 1052,
and determine the mass of the SMBH at the nucleus.
B
1
2
3
[email protected]
Universidade Federal do Rio Grande do Sul
Universidade Federal de Rio Grande
Universidade Federal de Santa Maria
371
Galaxies
Posters
GAL -2:
#176
Open Cluster Radial Velocity determination from observations at Observatório Pico
Dos Dias
Faria, M. A. F.B1 ; Monteiro, H.1 ; Dias, W. S.2 ; Lépine, J. R. D.3
In studies of the dynamics of the Galactic disk, such as the determination of the speed of the spiral pattern
and the permanence of stars in the spiral arms, it is crucial to know orbits obtained from proper motions,
radial velocities and the potential of the Galaxy. Aiming to improve the statistics of our catalog of open
clusters, maintained by our research group, we determined the radial velocity of stars belonging to a group
of open clusters using spectra with a resolution of 4000, obtained at the Pico dos Dias Observatory (LNA)
with the 1.60 m telescope and the Coudé spectrograph.
We observed the open cluster’s member stars and calculated their radial speeds using standard techniques. The stars were selected from our own database based on relevant information concerning the clusters, obtained by statistical analysis of their proper motions and/or their position in the HR’s diagram. In
this work, we present the detailed analysis of the data reduction and radial velocity determination using
synthetic spectra from different libraries. Finally we present the open cluster’s radial (and spacial) velocities.
B
1
2
[email protected]
Universidade Federal de Itajubá
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas
372
Posters
Galaxies
GAL -2:
#177
Effects of dark matter and energy on the chemical enrichment of Dwarf Spheroidal
Galaxies
Ferle, O. L.B1 ; Lanfranchi, G. A.1
We analyse several physical processes that may play important roles in the chemical enrichment and evolution of dwarf spheroidal galaxies by means of a detailed chemical evolution models and from results of
hydrodynamical simulation of dwarf galaxies. We adopted several different scenarios for the evolution of
the dwarf spheroidal galaxies by varying the prescriptions in the chemical evolution code for the mass and
distribution of dark matter, the star formation history and rate, and the energetic interaction among dark
matter, luminous matter, and gas. The adopted prescriptions are based on the results of the numerical simulations of the hydrodynamics of the gas content of the system. For each adopted scenario, the predictions
of the chemical evolution models are analysed and compared to the data. The occurrence and intensity of
galactic winds and their effect in the chemical properties are investigated by comparing the predictions with
observed data.
B
1
[email protected]
NAT - Universidade Cruzeiro do Sul, Brasil
373
Galaxies
Posters
GAL -2:
#178
The effects of the interaction on the kinematics and abundance of AM 2229-735
P. Freitas-LemesB1 ; I. Rodrigues1 ; O. L. Dors Jr.1 ; M. Faúndez-Abans2 ; E. Pérez-Montero3
We present an observational study of the effects of the interaction on the kinematics and chemical abundance of the component galaxies of AM 2229-735. This system is formed by a disk galaxy, NED01, and a
compact perturbed Sb(s)-like galaxy, NED02, the later showing a tail and counter-tail arc-shaped feature.
The sky projected tail is very luminous and seems to connect the galaxies. Our study was based on BVRI
broad band imagery as well as longslit spectroscopy in the wavelength range 4100-8600Å, performed at the
1.6m telescope at the Observatório do Pico dos Dias (OPD), Brazil. We have estimated heliocentric radial velocities of 17 518±25 km/s (NED01) and 17 326±27 km/s (NED02). Standard diagnostic diagrams were used
to classify the main ionizing source of selected emission-line regions. It turns out that all regions are mainly
ionized by massive stars. Using two empirical methods, we found that the H II regions in AM 2229-735 have
high metallicity: 12+log(O/H)=8.3-8.6 dex.
B
1
2
3
[email protected]
Universidade do Vale do Paraı́ba. Av. Shishima Hifumi, 2911, CEP: 12.244-000, São José dos Campos, SP, Brazil
MCT/Laboratório Nacional de Astrofı́sica, Caixa Postal 21, CEP:37.504-364, Itajubá, MG, Brazil
Instituto de Astrofisı́ca de Andalucı́a, CSIC, Apartado de correos 3004, 18080 Granada, Spain.
374
Posters
Galaxies
GAL -3:
#179
Low surface brightness galaxies and void walls
B1
Gaspar Galaz
; Laura Ceccarelli2 ; Rodrigo Herrera-Camus3 ; Nelson Padilla1 ; Diego Garcia-Lambas2
We present new results showing that low surface brightness galaxies (LSB) populate in significant larger fraction the walls which define the large scale structure voids in the cosmic web. Results were obtained using
data from the Sloan digital sky survey, and combined with simulations for analysis. Moreover, our results
show that at some poinf LSBs in void walls eventually evolve to high surface brightness galaxies.
B
1
2
3
[email protected]
Instituto de Astrofı́sica, P. Universidad católica de Chile
Observatorio Nacional de Córdoba
Universityvof Maryland
375
Galaxies
Posters
GAL -3:
#180
Rotation effects on the Lyman-alpha line morphology in distant galaxies
Garavito-Camargo, N.B1 ; Forero-Romero, J. E.1 ; Dijkstra, M.2
Rotation is present in the gas kinematics of galaxies up to the highest redshifts. In this talk we present for the
first time radiative transfer calculations that show the impact of rotation on the morphology of the Lyman
↵ line. To this end we construct simplified models where a galaxy is modeled as an homogeneous sphere
composed as an homogeneous mixture of dust and hydrogen at a constant temperature. These spheres have
a solid-body rotation with linear velocities at the surface in the range 0
300 km s
1
. We consider radiation
sources both in the center of the rotating cloud and also homogeneously distributed around the sphere. We
find that higher rotational velocities increase the width of each peak in the outgoing line profile while it also
increases the amount of Lyman alpha photons escaping in the line center. This trends makes that for high
rotational velocities and large Hydrogen optical depths the double peak of the line tends to be erased an be
replaced by a single peak the lines center. This is more pronounced for radiation sources homogeneously
distributed. Concerning the escape fraction we find that rotation does not have any effect, provided that all
the sources are centrally emitted. However in the case of homogeneously emitted sources we measure an
increase of about a factor of 2 in the escape fraction for higher rotational velocity values. Our work shows
clearly that gas rotation has a non negligible impact on the shape of the Lyman ↵ line.
B
1
2
[email protected]
Departamento de Fı́sica, Universidad de los Andes, Bogotá, Colombia
Institute for theoretical astrophysics, University of Oslo
376
Posters
Galaxies
GAL -3:
#181
Visualizing VVV catalogue and image data
Gurovich, SebastianB1,2 ; Samual Skillmann3
We are exploring python community-based methods to visualize multi-epoch data from the Vista Variables
in the Via Lactea Survey. Our efforts include use of the python YT and astropy modules to detect and characterize moving objects in the ecliptic as well as the light curve of periodic variables.
B
1
2
3
[email protected]
Observatório Astronómico de Córdoba, Universidad Nacional de Córdoba, Laprida 854, x5000 BGR, Córdoba, Argentina
Instituto de Astronomı́a Teórica y Experimental, CONICET, Laprida 922, 5000, Córdoba, Argentina
Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO, USA
377
Galaxies
Posters
GAL -3:
#182
Photometry and Dynamics of the Minor Merger AM 1219-430 with Gemini/GMOS-S
Hernandez-Jimenez, J. A.B1 ; Pastoriza, M. G.1 ; Rodrigues I.3 ; Krabbe, A. C.3 ; Winge, C.5 ; Bonatto, C.1
We present an observational study of the interaction effect on the dynamics and morphology of the minor
merger AM 1219-430. This work is based on r0 and g 0 images and long-slit spectra obtained with the Gemini Multi-Object Spectrograph at the Gemini South Telescope. We detected a tidal tail in the main galaxy
(AM 1219A) and a bridge of material connecting the galaxies. On the other hand, the secondary galaxy
(AM 1219B) shows prominent symmetric tidal tails. We separated the two-fold symmetric and the nonsymmetric parts of the galaxies by performing successive image rotations and subtractions. The symmetric
images, obtained by subtracting the asymmetric one from the observed image, show the “original” disk and
the non-perturbed spiral pattern. The overall geometrical parameters of the galaxies, such as inclination and
position angle of the line-of-nodes, were obtained from the photometric analysis of the symmetrized g0 and
r0 images. The surface brightness profile of AM 1219A was decomposed into bulge and disk components.
The profile shows a light excess of ⇠ 53% due to the contribution of star-forming regions, which is typical
of starburst galaxies. On the other hand, the surface brightness profile of AM 1219B shows a lens structure
in addition to the bulge and disk. The scale lengths and central magnitudes of the disk structure of both
galaxies agree with the average values derived for galaxies with no sign of ongoing interaction or disturbed
morphology. The Sérsic index (n < 2), the effective and scale radii of the bulge of both galaxies are typical of
pseudo-bulges. The rotation curve of AM 1219A derived from the emission line of ionized gas is quite asymmetric, suggesting a gas perturbed by interaction. The overall best-fitting solution for the mass distribution
+0.3
of AM 1219A was found with M/L for bulge and disk of ⌥b = 2.8+0.4
0.4 and ⌥d = 2.4 0.2 , respectively, and a
+1.2
12
Navarro, Frenk & White profile of M200 = 2.0+0.5
0.4 ⇥ 10 M and c = 16.0 1.1 .
B
1
2
3
[email protected]
Instituto de Fı́sica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
Universidade do Vale do ParaÍba, São José dos Campos, SP, Brazil
Gemini Observatory, La Serena, Chile
378
Posters
Galaxies
GAL -3:
#183
Physical properties of galaxies in the Sloan Digital Sky Survey detected in infrared
Herpich, F. R.B1 ; Mateus, A.1 ; Cid Fernandes, R.1 ; Lacerda, E. A.1 ; de Amorim, A. L.1 ; Rossi, L. L.2 ; Cendron, M. M2 ;
Klein, V. B.2 ; Crestani, T.2 ; Parize, M. M.2 ; Braz, F. J.3
The extragalactic astrophysics is experiencing a golden age with the availability of an almost inconceivable
amount of observational data and projects in different spectral regions. Our research group at UFSC, in collaboration with other researchers from Brazil and France, was successful in following these new challenges,
especially with the spectroscopic analysis of the SDSS data. The result of this effort was to build a database
of physical properties of galaxies to nearly 1 million objects, which is completely public. Recently we also
started analyzing data from the GALEX ultraviolet, spectral broadening our coverage. In this work, we continue this expansion, focusing our attention in the infrared region of the electromagnetic spectrum with the
inclusion of font catalogs obtained a recently mission, the WISE project. We increase our database with the
data obtained from the WISE and made the match in the catalog of creating a subsample of SDSS galaxies
about 300 000 objects. These objects are analyzed using a new computational tools in order to identify the
properties in the infrared. This is done in conjunction with the Department of Computer Science of Santa
Catarina Federal Institute. In the first analysis, we obtain a clear separation between star forming galaxies
(SF) and “retired” galaxies (RT). In this work, we present the latest results of the analysis of this data.
B
1
2
3
[email protected]
Universidade Federal de Santa Catarina - UFSC
Instituto Federal Catarinsense, campus Videira
Instituto Federal Catarinense, campus Araquari
379
Galaxies
Posters
GAL -3:
#184
SFR in dwarf spiral galaxies
Hidalgo-Gàmez, A. M.B1 ; Vega-Acevedo, I.1 ; Magaña-Serrano, M. A.1
In this investigation the SFR of a sample of 15 dwarf spiral galaxies (dS) is studied. They were obtained from
H↵ images from the 1.5m telescope at OAN-SPM (Mexico). The SFR values obtained for the dS galaxies,
of the order of 0.01 M yr
1
, are lower than for earlier spirals (e.g. Sd), being closer to those of irregular
galaxies. A study of the SFR vs. the gas mass density, as well as vs. the number of H II regions, the size of the
largest region, and the chemical abundance have been perfomed for the dS galaxies and it was compared
with the results for some other spiral galaxies. It is very interesting that, although one might think that dS
are just small, late-type, spiral galaxies they do not follow the trends of the other spirals. Neither they follow
the trend for irregular galaxies. Therefore, it might be considered as an intermediate type between the large
Sd-Sm galaxies and the irregular ones.
B
1
[email protected]
Escuela Superior de Fisica y Matemáticas, IPN, México
380
Posters
Galaxies
GAL -3:
#186
E+A galaxies in SDSS. Stellar population and morphology
Rodrigo LeivaB1
A sample of E+A galaxies from SDSS DR7 is selected by having a strong H absorption line and few H↵ and
[OII] emission lines.
The morphology and star formation history are studied. Visual classification and photometric light profile criteria are used as complementary approaches to determine the morphology using for the first the results from volunteer based classification project Galaxy Zoo 1. Also automatic light profile parameter determination published in SDSS are used as alternative approach. With the premise that E+A are post-starburst
(PSB) galaxies, star formation history is studied fitting synthetic spectra using Galaxev. Each galaxy is fitted
with two populations, an old composite stellar population and a recent single stellar population. This simple
fit is compared with the PSB hypothesis and compared with the more sophisticated fit from VESPA where a
complete star formation history is determined.
B
1
[email protected]
Instituto de Astrofı́sica, Pontificia Universidad Católica de Chile
381
Galaxies
Posters
GAL -3:
#187
High-redshift translucent clouds: detection of neutral species in QSO absorbers
López P.B1 ; López S.1 ; Sánchez P.1
We analyze a sub-sample of high-redshift Mg II absorption systems drawn from a sample of 900 MgII systems
detected in the ESO archive of VLT/UVES QSO spectra. In these particular systems we find absorption due
to Si I, Ca I, Fe I and other neutral species. The presence of such neutral species is not common, given their
low ionization potential, and suggests that the clouds are shielded from ionizing photons. Thus, these cold
neutral clouds could be the high-redshift precursors of the molecular clouds, where stars are born.
B
1
[email protected]
Universidad de Chile
382
Posters
Galaxies
GAL -4:
#188
SFH of galaxies using spectroscopy in the optical range of the CALIFA sample and
ultraviolet photometry of the GALEX mission
López-Fernández, R.B1 ; González Delgado, R. M.1 ; Cid Fernandes, R.2 ; Pérez, E.1 ; Garcı́a Benito, R.1
Why study the stellar populations? Different evolutionary processes leave a different fossil record in the
stellar population properties of galaxies. A very powerful method to study the formation and evolution of
galaxies is to reconstruct the star formation history through the properties of stars that form them. Currently
is used the evolutionary synthesis technique to infer the properties of the stellar population through the
integrated light of all the stars, assuming an initial mass function (IMF) and a star formation rate. To analyze the data we use the code STARLIGHT. The spectral range of the CALIFA sample is ideal for the study of
stellar populations, as it contains the lines of the Balmer series and the Balmer jump. However, the method
can present age-metallicity-extinction degenerations, producing uncertainties in determining the physical
properties of the stellar population characteristics. So we combine CALIFA spectroscopic data with photometric data in the ultraviolet range obtained with the GALEX mission in order to break these degeneracies,
including data that provide additional information about the young stellar populations, which contribute to
a lesser extent in the optical range.
B
1
2
[email protected]
Instituto de Astrofı́sica de Andalucı́a (CSIC), Camino Bajo de Huétor s/n Aptdo. 3004, E18080-Granada, Spain
Departamento de Fı́sica, Universidade Federal de Santa Catarina, P.O. Box 476, 88040-900, Florianópolis, SC, Brazil
383
Galaxies
Posters
GAL -4:
#189
The distribution of stellar populations within galaxies
Martins-Novais, P.B1 ; Sodré Jr., L.1
The study of stellar populations in galaxies is particularly interesting, since they are a fossil record of several physical processes associated with the formation and evolution of galaxies. In this work we present the
first results of our approach to study the spatial distribution of stellar populations inside galaxies. We are
using ugriz magnitudes and principal component analysis (PCA) to obtain pixel-by-pixel proxies of the stellar populations and their distributions inside each galaxy. The distribution of these populations are then
investigated with a variety of statistical tools, including Gini Indices and the Euler-Poincaré characteristic.
This approach is a step forward the conventional profile fitting and allows to obtain quantitative estimates
on how the different stellar populations are distributed within a galaxy, bringing hints on how galaxies grow
and evolve.
B
1
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas. IAG/USP
384
Posters
Galaxies
GAL -4:
#190
The environmental properties of galaxies probed by marked statistics
Mateus, A.B1
Galaxies are generally treated as point particles in clustering analysis. However, these objects have physical
and stellar population properties that must be taken into account if one wants to study the environmental
effects on galaxy evolution. In this work, we apply a statistical method to investigate the role of environment in driving galaxy properties based on the marked correlation function. This methodology was applied
for galaxy samples drawn from the Sloan Digital Sky Survey (SDSS) Data Release 7 and from the Wide-field
Infrared Survey Explorer (WISE). Our main aim is to reproduce environmental relations among galaxy properties for galaxy catalogues based purely on photometric data, evaluating the effects of errors in photometric
redshift estimations on analysis involving galaxy environment. We show that marked statistics are powerful
to reproduce environmental trends for variables like luminosities, star formation rates and mean stellar ages,
as well as to quantify the relative importance of them with respect to the environment.
B
1
[email protected]
Universidade Federal de Santa Catarina, Brazil
385
Galaxies
Posters
GAL -4:
#191
Submillimeter Galaxy Number Counts in a Semi-analytic Model: the ”Count Matching”
Approach
Muñoz Arancibia, A. M.B1 ; Navarrete, F.2 ; Padilla, N.1,3 ; Cora, S.4,5 ; Gawiser, E.6 ; Kurczynski, P.6 ; Ruiz, A.7
Fitting submillimeter galaxies (SMGs) into the current theory of galaxy formation has been a challenge since
their discovery, even though they are the most luminous star-forming sources at the epoch where galaxy
formation peaks. Recent ALMA observations of the Extended Chandra Deep Field South (for which LABOCA
detections are available) show that the bright end of the LABOCA number counts is actually comprised by
emission from multiple fainter sources, given the high sensitivity and resolution of ALMA maps compared
to LABOCA.
With the aim of exploring the properties of SMGs, and in analogy to the now-standard abundance matching approach, we perform a ”Count Matching” approach through lightcones drawn from a semi-analytic
model. We choose various physical galaxy properties given by the model as proxies for their submillimeter
fluxes, assuming a monotonic relationship so that the combined LABOCA plus bright-end ALMA observed
number counts are reproduced. After turning the catalogs of galaxy positions and fluxes given by the different proxies into submillimeter maps that include a modeling of the observational process, we perform
a source extraction as done for maps obtained through observations. With this we study the effects of the
observational process in the recovered counts, as well as the galaxy properties derived from the detected
sources for each proxy.
The difference between the counts with and without the beam of LABOCA can be used to find the best
proxy: sources with the highest submm fluxes will have different clustering depending on the assumed proxy,
since the sources with the highest value of a given property will be clustered in a particular way; the best
proxy then will be such that the clustering measured from the model galaxies is the same that the one given
by the ALMA sources, while the recovered clustering from the simulated maps is the same that the one given
by the LABOCA SMGs. This can also be confirmed exploring other statistics like redshift, stellar mass and
host halo mass distributions.
B
1
2
3
4
5
6
7
[email protected]
Departamento de Astronomı́a y Astrofı́sica, Pontificia Universidad Católica de Chile
Max-Planck-Institut für Radioastronomie
Centro de Astro-Ingenierı́a, Pontificia Universidad Católica de Chile
Consejo Nacional de Investigaciones Cientı́ficas y Técnicas de Argentina
Facultad de Ciencias Astronómicas y Geofı́sicas, Universidad Nacional de La Plata, e Instituto de Astrofı́sica de La Plata
Department of Physics and Astronomy, Rutgers
Observatorio Astronómico de Córdoba, Universidad Nacional de Córdoba
386
Posters
Galaxies
GAL -4:
#192
Properties of Galaxies and Groups at z < 1.4
Nascimento, R. S.B1 ; Lopes, P. A. A.1 ; Ribeiro, A. L. B.2
In this work, we analyse a sample of galaxy groups constructed from the fourth data release of the Deep
Extragalactic Evolutionary Probe 2 (DEEP2) including the Extended Groth Strip (EGS). This sample was obtained by Gerke et al. (2012) using the Voronoi-Delaunay Method. We selected 412 galaxy groups with at
least 8 members in a radius of 4Mpc. For each group we estimated its properties such as velocity dispersion ( ), physical radius (R200 ) and mass (M200 ). We also classify the groups as Gaussian and non-Gaussian
(dynamic evolved or not) based on their galaxy velocity distributions. This classification is based on the
following statistical tests: Anderson-Darling, Kolmogorov-Smirnov, Shapiro-Wilk, Jarque-Bera, Cramer-von
Mises, D’Agostino and Dip test. When the Dip test confirms the hypothesis of the unimodality and all other
tests prove the normality of the system, the group is classified as Gaussian. The behavior of gaussianity was
checked varying the distance to the center of the group in 2-4 times its physical radius. Our preliminary
results show that the number of systems classified as non-Gaussian groups grows with the increase of the
physical radius.
B
1
2
[email protected]
Observatório do Valongo, Universidade Federal do Rio de Janeiro
Laboratório de Astrofı́sica Teórica e Observacional, Universidade Estadual de Santa Cruz
387
Galaxies
Posters
GAL -4:
#193
Secular Evolution in Green Valley Galaxies
Nogueira-Cavalcante, J. P.B1 ; Menéndez Delmestre, K.1 ; Gonçalves, T. S.1
The distribution of galaxies in the color-magnitude diagram shows two distinct peaks: the red sequence and
the blue cloud. The red sequence is predominantly populated by early-type galaxies, whose stellar population is mostly old. Within the blue cloud most galaxies are late-types, where the dominant stellar population
is young.
Between these two peaks there is a sparsely populated region in the color-magnitude diagram known as
the green valley, which arguably represents an intermediate, brief stage in the evolution of galaxies. Several
factors can cause this rapid transition, including active galactic nuclei (AGNs) and mergers. There are observational evidences that these factors act differently in different epochs of the history of the universe. In
particular, Martin et al. (2007) and Gonçalves et al. (2012) pointed out that green valley galaxies evolve faster
at higher redshifts (z ⇠ 0.8), compared to those at low redshift (z ⇠ 0.2).
Bars play an important role in the secular evolution of galaxies, acting on a much longer timescale than
mergers and AGNs. We aim to trace the impact of secular evolution in the green valley by identifying bars
in green valley galaxies at z ⇠ 0.2 and z ⇠ 0.8. We here present this analysis for a small sample of z ⇠ 0.8
galaxies in the Extended Groth Strip (EGS) region imaged with the Hubble Space Telescope. In the future we
intend to extend this analysis to a wider sample of high-z green valley galaxies as well as to the low-z green
valley galaxy sample.
B
1
[email protected]
Observatório do Valongo, Universidade Federal do Rio de Janeiro
388
Posters
Galaxies
GAL -4:
#194
Low-redshift compact UV luminous starbursts: a door to understand high-redshift
Lyman-Break Galaxies
Oliveira, C. S.B1 ; Menéndez-Delmestre, K.2 ; Gonçalves, T. S.3
Lyman-break galaxies (LBGs) are a population of distant objects (z ⇠ 3) selected at rest-frame UV that rep-
resent the typical starburst galaxy at a time when the universe was going through its peak in star formation
activity. The star formation rates of LBGs suggest that these galaxies may be the progenitors of a large part
of the massive galaxies in the local universe, making them important objects of study. However, detailed
studies of the morphology and kinematics of these distant galaxies are limited by the sensitivity of current
instruments. We study a sample of low-redshift UV-selected supercompact starbursts that share many properties (morphology, surface brightness, luminosity) with high-redshift LBGs and are hence denominated as
Lyman-break Analogs (LBAs). These UV luminous galaxies (UVLGs) were recently uncovered by the Galaxy
Evolution Explorer (GALEX) satellite. At significantly lower redshifts (z ⇠ 0.2) than LBGs, they provide us
with a unique opportunity to draw analogies with their high-redshift counterparts and study in great detail
the astrophysical conditions that lead to the star formation activity we observe in the distant universe. We
have undertaken the near-IR photometric analysis of a sample of LBAs based on observations taken with
the Fourstar instrument on the 6.5m Baade Telescope (Las Campanas Observatory, Chile). We now extend
this work to the wider population of compact UVLGs, with surface brightness one or two orders of magnitude
than normal galaxies, but less extreme than supercompact UVLGs. Based on J, H, Ks, and optical photometry
for ⇠ 40 compact and supercompact UVLGs we are in the process of analyzing the spectral energy distribu-
tion (SED) of each individual galaxy to derive stellar masses and ages in order to explore the similarities and
differences between these two populations relative to normal galaxies in the local universe and to LBGs in
the distant universe.
B
1
[email protected]
Valongo Observatory, Federal University of Rio de Janeiro
389
Galaxies
Posters
GAL -4:
#195
An approach to measuring the density of the environment of galaxies: results and
comparisons with other measurements
René A. Ortega-MinakataB1 ; Juan P. Torres-Papaqui1 ; H. Andernach1
With the aim of obtaining a homogeneous and reliable measurement of the density of the environment of a
large sample of galaxies, we have written a code that counts the number of neighbouring galaxies around a
target galaxy. As targets, we have selected a large sample of galaxies from the spectroscopic catalogue of the
SDSS-DR7 with with redshifts between 0.03 and 0.30. The photometric catalogue of the SDSS-DR7 was used
to extract and count the neighbouring galaxies from, including all objects for which a photometric redshift
was available to serve as a distance estimate. The code counts all galaxies within an absolute distance of 1.5
Mpc around the target (translated to an apparent radius and a redshift range of the neighboring galaxies,
based on the redshift of the target). We only count galaxies more luminous than an absolute magnitude of
19 in the SDSS r band. Within the mentioned redshift and magnitude limits, and in the North Galactic region
of the SDSS, there are about 600K target galaxies and about 24M in the neighbouring galaxies sample.
We present our results and compare them to other measurements of the density of the environment of
galaxies, such as given by the MaxBCG catalogue of brightest cluster galaxies. As a control of our method,
we apply it to a sample of galaxies from the 2MIG catalogue of isolated galaxies, and also to a sample of
galaxies from a compilation of members of Abell clusters. We aim to use our results to test the morphologylocal density relation and to study the relationship between the different types of emission-line activitiy of
galaxies and the density of their environment.
B
1
[email protected]
Departamento de Astronomı́a, Universidad de Guanajuato, Mexico
390
Posters
Galaxies
GAL -4:
#196
A kinematic study of different stellar populations in the irregular NGC 6822
M. PeñaB1 ; S. Flores-Durán1 ; L. Hernández-Martı́nez1 ; J. Garcı́a-Rojas2
The kinematics of planetary nebulae (PNe) in in our own and other galaxies and , is a clue to understand
the behavior of the low-intermediate mass stars and their relation with other galactic components. Highresolution spectroscopy of a significant sample of PNe (intermediate-age population) and HII regions (young
objects) in the irregular galaxy NGC 6822 is analyzed, aiming to determine if both populations share the kinematics of the HI disk found in this galaxy. Observations were made with the Magellan telescope (MIKE spectrograph) and the 2-m telescope of SPM-OAN (MES spectrograph). The data have a resolution better than 10
km/s. The analysis shows that HII regions and other members of the young stellar population follow closely
the rotation of the HI disk. On the contrary, PNe are not moving along with the HI gas and their kinematics
is closer to the behavior of the spheroid of C stars, which is a system with different spatial distribution and
kinematics. Thus we confirm that the irregular galaxy NGC6822 has at least two very different kinematical
systems. In the future we plan to use the kinematics of these systems to model the distribution of the dark
matter halo in this galaxy.
B
1
2
[email protected]
Instituto de Astronomı́a, UNAM, México
Instituto de Astrofı́sica de Canarias, Spain
391
Galaxies
Posters
GAL -5:
#197
Mapping Triangulum-Andromeda with the SDSS
B1,5
Perottoni, H. D.
; Rocha-Pinto, H. J.1,5 ; Girardi, L.4,5 ; Balbinot, E.3,5 ; Santiago, B. X.3,5 ; Da Costa, L.2,5 ; Maia, M. A. G.2,5
The last decade has brought the first data releases of some large astronomical surveys (e.g., 2MASS, RAVE,
SDSS), which allowed the discovery of several stellar overdensities in the Galactic halo. One of this overdensities is Triangulum-Antromeda (TriAnd), which was found by Rocha-Pinto et al. (2004) and Majewski et al.
(2004) using a sample 2MASS M giants candidates. The existence of such overdensities argues against the
canonical homogeneous stellar halo coming from the classical ELS model for the formation of the Galaxy;
they point to a halo partially formed by tidal debris from former satellites galaxies of the Milky Way. TriAnd
is a very diffuse cloud-like substructure - it contains approximately 1 M giant per deg2
o
o
o
spread over a large
o
area between 100 < l < 150 and -10 > b > -50 . Due to its patchy density, the structure could not be
well mapped with 2MASS M Giants by Rocha-Pinto et al. (2004); it is not clear whether it has a core or not.
Despite the number of years since this discoveries, TriAnd is still not well known. In order to gain a better
understanding about the origin of this structure, we are mapping it using photometric data from the SDSS
DR9 and comparing the observations with simulations from the TRIdimensional modeL of thE GALaxy (TRILEGAL; Girardi et al. 2005).
B
1
2
3
4
5
[email protected]
OV/UFRJ
ON/MCT
UFRGS
Osservatorio Astronomico di Padova
LINEA
392
Posters
Galaxies
GAL -5:
#198
Galaxy Model in Infrared
Polido, P.B1 ; Jablonski, F.1
We present in this work a new approach to the derivation of galactic parameters via the star counts method.
It uses a modern version of the model of Ortiz & Lépine (1993) and the 2MASS data in J, H and KS to estimate,
based on a regular grid of lines-of-sight over the whole sky, the most important structural parameters of the
Galaxy. It is the first time that the star counts method is used in the whole sky, including the complex region of
the galactic plane. We have used a conservative approach to derive parameter values and their uncertainties,
and also investigate the effects of using several limiting magnitudes over the best set of parameters which
describes the Galaxy. Since the landscape for the figure of merit of a model can be pretty complex when we
have a number of free parameters in excess of a dozen, the Markov Chain Monte Carlo method looks like
ideal for an overview of the parameter space, to constrain regions of interest for further exploration and to
provide realistic uncertainties. The pinpointing of the best parameter values is carried out with the Nested
Sampling method, very robust in terms of progression to the optimum solution of a multiparameter model.
B
1
[email protected]
Instituto Nacional de Pesquisas Espaciais
393
Galaxies
Posters
GAL -5:
#199
Physical parameters of galaxies with star formation through mid-infrared SED models
Andrés F. Ramos P.B1 ; J. R. Martı́nes-Galarza2 ; Mario-A. Higuera-G.3 ; Seditsira Quintero4
We present a multiwavelength study of a sample of 22 starburst galaxies and derive physical parameters
using Bayesian SED fitting. We take into account the emissions of the Polycyclic Aromatic Hydrocarbons
(PAHs), as well as the total bolometric luminosities of the observed galaxies. We use state of the art SED
models, as a necessary tool in order to investigate physical properties. Our study of this local sample of
galaxies helps in the understanding of massive star formation through cosmic history. Using a Bayesian fitting routine, we fit the Spitzer-IRS spectra of local (z<0.5) galaxies in the range of 5 to 35 µm, complemented
with infrared photometry obtained by the Spitzer Space Telescope and the Herschel Space Observatory. We
derive marginalized probability distribution functions (PDFs) for model parameters. We calculate metallicity, interstellar medium pressure, star formation rates (averaged over 1, 10 and 100 Myr), compactness
C (related to the dust heating flux), PDR fraction fP DR , extinction AV and attenuation of diffuse dust. We
compare the derived parameters and search for galaxy to galaxy correlations between them. Finally, we also
study the correlations between our derived parameters and nebular line emission from atomic species. With
this study we aim at relating the global star-forming properties of these galaxies to the internal physics at the
level of individual HII regions. Our 22 galaxies are an excelent comparison sample for star-forming galaxies
at higher redshifts.
B
1
2
3
4
[email protected]
Department of Physics, National University of Colombia, Ciudad Universitaria, Bogotá D.C., Colombia
Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-51, Cambrigde, MA 02138, USA
National Astronomical Observatory, National University of Colombia, Ciudad Universitaria, Bogotá D.C.,Colombia
Department of Mathematics, National University of Colombia, Ciudad Universitaria, Bogotá D.C., Colombia
394
Posters
Galaxies
GAL -5:
#200
Disk Mass-to-light Ratio Distribution from Stellar Population Synthesis: Application to
Rotation Curve Decomposition of NGC 5278
Repetto, P.B1 ; Martı́nez-Garcı́a, Eric E.2,3 ; Rosado, M.2 ; Gabbasov, R.2
In this work we extend the study on the mass distribution of the spiral galaxy NGC 5278, performing 1D and
2D (GALFIT) bulge-disk decomposition to determine which components constitute the baryonic mass in
this galaxy. Our analysis does not detect any bulge; instead we find a bright source probably related to the
central active galactic nucleus and an exponential disk. We fix the stellar disk contribution to the rotation
curve (RC) with broadband photometric observations and population synthesis models, to obtain the 2D
mass distribution of the stellar disk. In the particular case of NGC 5278, we find that the typical assumption of
considering the mass-to-luminosity ratio (M/L) of the disk as constant along the galactocentric radius is not
valid. We also extract a baryonic RC from the mass profile to determine the inability of this baryonic RC and
also the baryonic RC with more than and less than 30% disk mass (in order to consider the disk mass errors)
to fit the entire RC. We perform the RC decomposition of NGC 5278 by considering the baryonic RC and
four types of dark matter (DM) halo: Hernquist, Burkert, Navarro, Frenk, & White, and Einasto. Our results
determine that the Hernquist DM halo better models our observed RC in the case of disk mass Md = 5.6⇥1010
M and also with less than 30% disk mass. In the case of more than 30% disk mass, the cored Einasto (n < 4)
DM halo is the best-fitting model.
B
1
2
3
[email protected]
Laboratorio Nacional De Astrofisica, R. Estados Unidos 154, Barrios das Naçoes 37.504-364, Itajuba-MG
Instituto de Astronomı́a, Universidad Nacional Autónoma de México (UNAM), Apdo. Postal 70-264, 04510 México, D.F., Mexico
Instituto Nacional de Astrofı́sica, Óptica y Electrónica (INAOE), Aptdo. Postal 51 y 216, 72000 Puebla, Pue., Mexico
395
Galaxies
Posters
GAL -5:
#201
AM2217-490: Uma galáxia com anel polar em formação
Priscila Freitas-Lemes1 ; Irapuan RodriguesB1 ; Maximilliano Faúndez-Abans2 ; Oli Dors1
O presente trabalho é parte de uma série de estudos de caso de Galáxias com Anel Polar (PRG, do inglês: ”Polar Ring Galaxy”). Uma PRG é formada por uma galáxia hospedeira do tipo precoce, lenticular ou elı́ptica,
rodeada por um anel de gás e estrelas orbitando um plano aproximadamente perpendicular ao plano principal da galáxia hospedeira). AM2217-490 é um caso interessante de PRG em formação, com um anel ainda
assimétrico que rodeia a galáxia hospedeira. Ao que tudo indica, essa estrutura azulada (que é caracterı́stica
dos anéis das PRGs), ainda não está em equilı́brio com a galáxia hospedeira. O presente estudo, ainda em
fase preliminar, se baseia em espectros de 6250 - 7250 Å obtidos no telescópio de 1.5m do CTIO - Chile. A
partir deles, medimos a velocidade heliocêntrica do sistema: 9152 ± 18 km/s. Diagramas de diagnóstico
apontam que a região nuclear da galáxia se comporta como uma região HII. Os valores médio encontrados
são: log(NII/H↵ ) = -0.16 e log(SII/H↵ ) = -0.69. O seu parâmetro de ionização (log U = -2,99), é similar ao valor
encontrado em galáxias isoladas. Entre as PRGs estudadas até o momento, várias delas apresentam atividade
nuclear. Se a atividade nuclear nas PRGs é desencadeada pela queda de gás durante a formação do anel polar, é compreensı́vel que no caso de AM2217-490 ela ainda não tenha ocorrido, pois seu anel ainda está em
formação. As imagens de baixa resolução do SDSS não mostram pontes ou caudas que liguem a galáxia a
outros objetos, entretanto, em um raio de 5 arcmin existem 3 outras galáxias com velocidades similares, caracterizando um grupo. Uma hipótese plausı́vel é que dessas galáxias pode ter interagido com AM2217-490,
doando material para a formação do anel.
B
1
2
[email protected]
Universidade do Vale do Paraı́ba - UNIVAP
Laboratório Nacional de Astrofı́sica - LNA/MCTI
396
Posters
Galaxies
GAL -5:
#202
Determination of Halo Occupation Distribution
Rodriguez, F.B1 ; Sgró, M. A.1 ; Merchán, M.1
The current paradigm assumes that galaxies form within dark matter halos. However, the diversity of astrophysical mechanisms involving in galaxy formation do not allow to determine how many galaxies lie in a
halo of a given mass. In this context, the Halo Occupation Distribution (HOD) gives the probability that a
halo of mass M contains N galaxies and allows associate, in a statistics way, the amount of galaxies residing
in a halo. In this work, we propose a method of background subtraction for calculate the HOD. This allows
to combine spectroscopic information from catalogs of galaxy groups with photometric information from
a catalog of galaxies. To evaluate the procedure, we used mock catalogs of galaxies and groups constructed
with a imposed HOD. We compare this fiducial HOD with the obtained results by applying our method.
Finally, we implement background subtraction in the Sloan Digital Sky Survey DR7.
B
1
[email protected]
Instituto de Astronomı́a Teórica y Experimental (UNC-CONICET), Observatorio Astronómico de Córdoba.
397
Galaxies
Posters
GAL -5:
#203
Effects of interaction in chemical evolution and stellar population of galaxy pairs
Rosa, D. A.B1 ; Dors Jr., O. L.1 ; Krabbe, A. C.1 ; Pastoriza, M. G.2 ; Winge, C.3 ; Hägele, G. F.4,5 ; Cardaci, M. V.4,5
In this work we present a study about the influence of interactions on the metallicity, traced by the oxygen
abundance of the gas phase, and on the stellar population in a sample of galaxy pairs. We used data of long
slit spectroscopy in the spectral region 3000-7000 Åobtained with the GMOS/Gemini South telescope for a
sample of six pairs of galaxies. These data were combined with stellar population synthesis models using the
program STARLIGHT and a grid of photoionization models built with the Cloudy code. We found that some
objects are dominated by younger populations with up to 500 billion years and other have a profile along the
disk with stellar population composed of heterogeneous elements. We derived flatted oxygen abundance
gradients in the interacting galaxies, with values in consonance with the solar value (i.e. 12+log(O/H)=8.7).
We conclude that interactions change significantly the chemical evolution and the history of star formation
of galaxy pairs.
B
1
2
3
4
5
[email protected]
Universidade do Vale do Paraı́ba, Av. Shishima Hifumi, 2911, Cep 12244-000, Brazil
Instituto de Fı́sica, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, Cep 91359-050, Porto Alegre, RS, Brazil
Gemini Observatory, c/o AURA Inc., Casilla 603, La Serena, Chile
Instituto de Astrofı́sica de La Plata (CONICET La Plata–UNLP), Argentina
Facultad de Ciencias Astronomicas y Geofısicas, Universidad Nacional de La Plata, Paseo del Bosque s/n, 1900 La Plata, Argentina
398
Posters
Galaxies
GAL -5:
#204
The dense gas in M82
B1
Salas, P.
; Galaz, G.1 ; Bolatto, A.2 ; Salter, D.2 ; Herrera, R.2
Understanding how galaxies evolve is one of the major goals of modern astronomy. In order to obtain an
integral understanding of how galaxies evolve there is a need to understand how different physical processes
shape the ISM. One of these processes is that of star formation, which can be studied through observations
of dense gas. The key question regarding galactic evolution is to know how different high density molecular
tracers allow us to study the star-forming conditions of their hosts. Studying how different star formation
indicators change over different physical scales is the question we want to address. In order to study the
properties of the star-forming disk present in the prototypical starburst galaxy M82 we have obtained 3 mm
maps of 6 high density tracers using CARMA. Our maps have resolutions of 6”x6” (⇠ 100 pc at the distance
of M82), allowing us to study its structure in detail. The properties of the central star-forming disk reveal
a picture consistent with the model of an evolutionary sequence for starburst galaxies as traced by their
molecular gas abundances. Our higher resolution, compared to previous surveys, allows us to study how
these abundances change on smaller scales.
B
[email protected]
Instituto de Astrofı́sica, Facultad de Fı́sica, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 782-0436 Macul,
Santiago, Chile
2 Department of Astronomy and Laboratory for Millimeter-Wave Astronomy, University of Maryland, College Park, MD 20742, USA
1
399
Galaxies
Posters
GAL -5:
#205
PAH lines at high redshift as galaxy evolution marker
Santos, J. H. B.B1 ; Friaça, A. C. S.1
Based in chemodinamycal models for galaxy evolution, we studied the formation of PAH lines at high redshifts. The model considers carbon and silicon grains, and also PAH molecules. It distinguishes diffuse ISM
the molecular clouds associated to star forming regions. The PAH lines provide a good signature of the evolutionary stage of galaxies, star formation rate, in addition to allowing the assessment the relative importance
for of AGN and stellar emission on the output of the galaxy. In particular, the line ratio 11.3/7.7 µm is a good
marker of the age of high redshift galaxies. We expected that our calculations provide some benchmarks
both for future observations both with ground and satellite instruments. The ages derived in this way for
high redshift objects could be used to test dark energy models. In addition to the cosmological applications,
the observations of the PAH features could be used to check the charge state of PAHs. Apparently, anions
and neutrals are favored over cations.
B
1
[email protected]
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, Universidade de São Paulo (IAG-USP)
400
Posters
Galaxies
GAL -6:
#206
The mass–metallicity–star formation rate relation under the STARLIGHT microscope
Schlickmann, M. S.B1 ; Vale Asari, N.1 ; Fernandes, R. C.1 ; Stasinska, G.2
The correlation between stellar mass and gas-phase oxygen abundance (M –Z relation) has been known for
decades. The slope and scatter of this trend is strongly dependent on galaxy evolution: Chemical enrichment
in a galaxy is driven by its star formation history, which in turn depends on its secular evolution and interaction with other galaxies and intergalactic gas. In last couple of years, the M –Z relation has been studied as a
function of a third parameter: the recent star formation rate (SFR) as calibrated by the H↵ luminosity, which
traces stars formed in the last 10 Myr. This mass–metallicity–SFR relation has been reported to be very tight.
This result puts strong constraints on galaxy evolution models in low and high redshifts, informing which
models of infall and outflow of gas are acceptable. We explore the mass–metallicity–SFR relation in light of
the Sdss–starlight database put together by our group. We find that we recover similar results as the ones
reported by authors who use the MPA/JHU catalogue. We also present some preliminary results exploring
the mass–metallicity–SFR relation in a more detailed fashion: Starlight recovers a galaxy’s full star formation
history, and not only its recent SFR.
B
1
2
[email protected]
Departamento de Fı́sica - CFM - Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
LUTH, Observatoire de Paris, CNRS, Université Paris Dieterot, Place Jules Janssen, 9210 Meudon, France
401
Galaxies
Posters
GAL -6:
#207
MagAl: A new tool to analise galaxies photometric data
Schoenell, W.B1 ; Benitez, N.1 ; Cid Fernandes, R.2
On galaxy spectra, one can find mainly two features: emission lines, which tell us about the ionised gas content, and the continuum plus absorption lines, which tell us about the stellar content. They thus allow us
to derive gas-phase abundances, the main radiation sources, chemical enrichment and star formation histories. Braad-band photometry, on the other hand, is much more limited and hinders our ability to recover
a galaxy’s physical properties to such a degree of detail. However, with the recent development of redshift
surveys using the technology of ultra-narrow filters (⇡ 100 Å), such as ALHAMBRA, J-PAS and DES, it will be
invaluable to be able to retrieve information on physical properties of galaxies from photometric data.
Motivated by this data avalanche (which goes up to the petabyte scale), we decided to build our own
SED-fitting code: Magnitudes Analyser (MagAl), which has three modules. 1) A template library generation module: generates empirical and theoretical template libraries. 2) Bayesian fitting module: calculates
probability distribution functions (PDFs) for given observed and library template data. This is similar to the
method to measure photometric redshifts by Benitez (2000). 3) A result-analyser module: streamlines data
analysis from the large output PDFs files. A fourth module to manage 3D data is being developed and a few
preliminary tests are also shown.
To investigate the reliability of results obtained by MagAl, we have created a mock galaxy sample for the
ALHAMBRA survey filter system (http://alhambrasurvey.com) and tried to recover their physical properties.
We show that for our sample of simulated galaxies we can measure stellar ages, metallicities and extinctions
with a precision of less than 0.3 dex. Also, we apply the code to the ALHAMBRA survey catalog and show that
we can measure stellar masses with an accuracy of 0.2 dex when comparing to previous results like COSMOS
masses measured by Bundy et al. (2006).
B
1
2
[email protected]
Instituto de Astrofı́sica de Andalucı́a - CSIC
Departamento de Fı́sica, Universidade Federal de Santa Catarina
402
Posters
Galaxies
GAL -6:
#208
The NEBULATOM cookbook
Stasinska, G.B1 ; Morisset, C.2
We present a series of problems on nebular physics with detailed comments and solutions in python. Their
aim is to lead the student to a better understanding of the respective roles of the different processes at play
in ionized nebulae, and to use with proper insight some tools that have been developed for the analysis of
nebulae.
These exercises have been proposed at the NEBULATOM workshop in Choroni (Venezuela, 3-16 March
2013), a capacity development workshop for Latin American astronomers on emission-line objects in the
Universe.
B
1
2
[email protected]
LUTH, Observatoire de Paris, CNRS, Université Paris Diderot, Place Jules Janssen, 92190 Meudon, France
Instituto de Astronomı́a, Universidad Nacional Autónoma de México, Apdo. Postal 70264, Méx. D.F., 04510 Mexico, Mexico
403
Galaxies
Posters
GAL -6:
#209
Physical conditions and kinematics of an HII galaxy with extraordinary dense nucleus:
Mrk 996
Eduardo TellesB1 ; Trinh X. Thuan2 ; Yuri I. Izotov3 ; Eleazar Rodrigo Carrasco4
We present an integral field spectroscopic study with the Gemini Multi-Object Spectrograph (GMOS) of
the unusual blue compact dwarf (BCD) galaxy Mrk 996. We show through velocity and dispersion maps,
emission-line intensity and ratio maps, and by a new technique of electron density limit imaging, that the
ionization properties of different regions in Mrk 996 are correlated with their kinematic properties. From the
maps, we can spatially distinguish a very dense high-ionization zone with broad lines in the nuclear region,
and a less dense low-ionization zone with narrow lines in the circumnuclear region. Four kinematically distinct systems of lines are identified in the integrated spectrum of Mrk 996, suggesting stellar wind outflows
from a population of WR stars in the nuclear region, superposed on an underlying rotation pattern. From
the intensities of the blue and red bumps, we derive a population of ⇠473 WNL stars and ⇠98 WCE stars in
the nucleus of Mrk 996, resulting in a high N (WR)/N (O+WR) of 0.17.
We derive, for the outer narrow line region, an oxygen abundance12+log(O/H)=7.94±0.03 (⇠ 0.2 Z )by
using the direct Te method derived from the detected narrow [O III] 4363 line. The nucleus of Mrk 996 is
however nitrogen-enhanced by a factor of ⇠20, in agreement with previous CLOUDY modeling. This ni-
trogen enhancement is probably due to nitrogen-enriched WR ejecta, but also to enhanced nitrogen line
emission in a high-density environment. Although we have made use here of two new methods (PCA tomography and a method for mapping low- and high-density clouds) to analyze our data, new methodology
is needed to further exploit the wealth of information provided by integral field spectroscopy.
B
1
2
3
4
[email protected]
Observatorio Nacional, Rua Jose Cristino, 77, Rio de Janeiro, RJ, 20921-400, Brazil
Astronomy Department, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904, USA
Main Astronomical Observatory, Ukrainian National Academy of Sciences, Zabolotnoho 27, Kyiv, 03680, Ukraine
Gemini Observatory/AURA, Southern Operations Center, Casilla 603, La Serena, Chile
404
Posters
Galaxies
GAL -6:
#210
Metallicity gradients in tidal tails and merging systems
B1
Torres-Flores, S.
; Scarano Jr, S.2 ; Mendes de Oliveira, C.3 ; de Mello, D. F.4 ; Amram, P.5 ; Plana, H.6 ; Alfaro, M.1 ;
Olave, D.1
Interacting systems are ideal laboratories to study galaxy evolution. During the collision process, gas coming
from different regions of interacting galaxies can mix, producing a flattening in the radial distribution of
metals in these systems. In this talk, we present an analysis of the metal distribution in the tidal tails of three
interacting systems: NGC 92, NGC 2782 and NGC 1487. We also have studied the main body of the merger
system HCG 31. Using Gemini/GMOS spectroscopic data, we found no metallicity gradients for the tails of
the systems NGC 92 and NGC 2782, which suggests that gas mixing triggered by the interaction produces a
flattening in the original metallicity gradient of these systems. A similar scenario was detected in the central
region of the merger HCG 31. Our results suggest that a fraction of the enriched gas that was originally
located in the center of the interacting galaxies was expelled into the tidal tails when the interacting process
that formed the tail happened.
B
1
2
3
4
5
6
[email protected]
Universidad de La Serena, Chile
Universidade Federal de Sergipe, Brazil
Instituto de Astronomia, Geofı́sica e Ciencias Atmosféricas da Universidade de Sao Paulo, Brazil
Catholic University of America, Washington, USA
Laboratoire d’Astrophysique de Marseille, France
Universidade Estadual de Santa Cruz, Brazil
405
Galaxies
Posters
GAL -6:
#211
FIR/Radio correlation for different systems of galaxies
Vena Valdarenas, R. R.B1 ; Valotto, C.1,2
We present preliminary results from the statistical analysis of the correlation between the radio and far infrared fluxes in different samples of groups and clusters of galaxies, and isolated galaxies. We use 1.4 GHz
fluxes from the NRAO VLA Sky Survey (NVSS) and Faint Images of the Radio Sky at Twenty centimiters
(FIRST), and infrared fluxes at 12, 24, 60 and 100 microns from Infrared Astronomical Satelite (IRAS) and
12 and 22 microns from the Wide-field Infrared Survey Explorer (WISE). We show variations on the behavior
of this correlation for the different samples. This correlation has been studied by several authors for different
samples isolated galaxies and groups of galaxies.
B
1
2
[email protected]
Instituto de Astronomı́a Teórica y Experimental
Observatorio Astronómico de Córdoba, Universidad Nacional de Córdoba
406
Posters
Galaxies
GAL -6:
#212
The lost population of post-starburst galaxies
Werle, A.B1 ; Mateus, A.1
Post-starburst (PSB) galaxies comprise a class of objects that show strong traces of young stellar populations
in their spectra, but no sign of ongoing star formation. Their star formation histories (SFH) indicate that
these galaxies stopped forming stars in the past 1.5 Gyr. Samples of PSB galaxies are usually generated by
selecting spectra with strong Balmer absorption lines, but no detectable emission lines that characterize
star formation (e.g. [OII] 3727 and H↵). The usual criterion to limit star formation is to set the equivalent
width of the H↵ emission line to be smaller than 5 Å (Goto el al. 2004). Post-starburst galaxies identified in
the Sloan Digital Sky Survey (SDSS) by requiring minimal H↵ equivalent width generally exhibit weak but
nonzero emission lines with typical ratios of Active Galaxy Nuclei (AGN) hosts. This suggests that most PSB
galaxies may harbor “low-ionization nuclear emission-line regions” (LINERs) and, more rarely, Seyferts (Yan
et al. 2008).
In this research, we use the STARLIGHT spectral synthesis code (Cid Fernandes et al. 2005) to compute the fraction of light coming from young stellar populations, here denoted by fy , in a volume-limited
sample from the SDSS DR7 catalog. We then classify as PSB those galaxies with fy larger than 80% and
log([NII] 6584/H↵) higher than
0.4. This second criterion select galaxies without current star formation
(Cid Fernandes et al. 2011). When plotting this sample in the BPT diagram, we identify a high occurrence
of LINER and Seyfert hosts, as found by Yan et al. (2008). However, we show that a large amount of poststarburst galaxies with low emission lines are in fact passive galaxies, frequently misclassified as weak AGN
hosts.
B
1
[email protected]
Grupo de Astrofı́sica, Universidade Federal de Santa Catarina, Brazil
407
Galaxies
Posters
GAL -6:
#213
Galaxy Detection Behind the Milky Way using the VVV Survey
Baravalle, L.B1 ; Alonso, M. V.2,3 ; Nilo Castellon, J. L.2,4
Our participation in the VVV survey (Vista Variables in the Vı́a Láctea ) gives us a great opportunity to study
the distribution of galaxies, obscured by the presence of our Galaxy. The survey includes observations in
five near-infrared passbands of the bulge and part of the disk of the Galaxy. This work consists of the d115
TILE analysis looking for extended objects. We study the star-galaxy separation and we obtain photometric
properties of extended objects. As a first step, we also perform a visual inspection of these images, finding
205 candidates for galaxies. Our main goal is to automatically detect these extended objects and to separate
them in a photometric way. We analyse different regions in the Color- Magnitude and Color-Color Diagrams.
B
1
2
3
4
[email protected]
Facultad de Matemática, Astronomı́a y Fı́sica, Universidad Nacional de Córdoba (UNC)
Instituto de Astronomı́a Teórica y Experimental (IATE-CONICET), Córdoba
Observatorio Astronómico de Córdoba, UNC
Departamento de Fı́sica, Facultad de Ciencias, Universidad de La Serena, Cisternas 1200, La Serena, Chile
408
Posters
Galaxies
GAL -6:
#214
Confirmation of a cluster of galaxies hidden behind the Galactic bulge using the VVV
Survey
Minniti, D.1 ; Hempel, M.1 ; Ivanov, V. D.2 ; Coldwell, G.B3,4 ; Alonso S.3,4 ; Duplancic, F.3,4
We report the confirmation of a rich cluster of galaxies located behind the Milky Way bulge using the VVV
Survey database. This year the X-Ray satellites SUZAKU and CHANDRA discovered an X-ray cluster of galaxies located in the crowded regions of the bulge. The near-infrared photometry of the VVV survey allowed us
to provide infrared confirmation of this cluster. We build a deep near-infrared image of the field based on
30 different epochs. We also present color-magnitude and color-color diagrams using SExtractor, and device
specific criteria based on colors and morphology to select the galaxies among the numerous stellar sources
in the foreground. We find two dozen candidate galaxies, from which the cluster red sequence can be identified. Using all the information available, we also estimate the total extinction along this line of sight towards
the bulge.
B
1
2
3
4
[email protected]
Instituto de Astrofisica, Pontificia Universidad Catolica de Chile, Santiago, Chile
European Southern Observatory, Santiago, Chile
ICATE - CONICET
FCEFyN - Universidad Nacional de San Juan
409
Galaxies
Posters
GAL -7:
#215
Subhalo abundance matching in different Semi Analytic Models
Contreras, S.B1,2 ; Baugh, C. M.2 ; Norberg, P.2 ; Padilla, N.1
Semi-analytic models (SAMs) have become one of the most useful tools to study galaxy formation and evolution, and that is why we decided to study two of the most advanced SAMs available today, the Guo model
from MPA (Guo et al. 2011) and the Lagos models from Durham University (Lagos et. al. 2012) using subhalo
abundance matching (SHAMs) for several physical properties of the galaxies and for different redshifts. We
find a good agreement between the models for the properties of galaxies typically well reproduced by SAMs
(like stellar mass or r-band magnitude) by construction, but we find a less good agreement between the
models for other properties such as cold gas, SFR, U-band magnitude and black hole mass, demonstrating
that even though some predictions from semi-analytic models are consistent, some still have not reached a
unique prediction from different groups.
B
1
2
[email protected]
Instituto de Astrofı́sica, Pontificia Universidad Católica de Chile
Institute for Computational Cosmology, Department of Physics, Durham University
410
Posters
Galaxies
GAL -7:
#216
Potential-Density Pairs for Thin Disks and Spheroidal Haloes I: Expansion in
Chevishev Type I Polinomials
Cortés-Serrano, F.B1 ; González, G. A.; Reina, J. I.
We present an infinite family of power-density pairs for galaxy models composed by thin disks and spheroidal
haloes. In order to obtain the models, we first introduce the oblate spheroidal coordinates, which adapt in
a natural way to the geometry of the model. On crossing the disk, one of the oblate coordinates present
a change of sign without changing their absolute value, leading so to a finite discontinuity of the normal
derivative of the potential across the disk. Accordingly, we can obtain the surface mass density of the disk
by applying the Gauss law across the disk and the density of matter of the spheroidal halo by computing
means of the Poisson equation. The models are then obtained by expressing the gravitational potential as a
superposition of products of the Legendre functions of second class with the Chevishev Type I polynomials.
Given a solution for the potential with these characteristics, we obtain the corresponding expressions for the
density of the spheroidal halo of matter, the surface density of the disk and the circular velocity or rotation
curve.
B
1
[email protected]
Escuela de Fı́sica, Universidad Industrial de Santander
411
Galaxies
Posters
GAL -7:
#217
Triplets of galaxies: A connection with compact groups?
Duplancic, F.B1,2 ; O’Mill, A. L.3 ; Lambas, D. G.4,2 ; Sodré, L.3 ; Alonso, S.1,2
We analyse a sample of 71 triplets of luminous galaxies derived from the work of O’Mill et al. (2012). The
triplets are restricted to have members with spectroscopic redshifts in the range 0.01 < z < 0.14 and Mr <
20.5. We compare the properties of triplets and their members with those of control samples of compact
groups, the ten brightest members of rich clusters, and galaxies in pairs. Our analysis suggest that triplet
galaxy members behave similarly to compact group members and galaxies in rich clusters. We also find that
systems comprising 3 blue, star-forming, young stellar population galaxies (blue triplets) are most probably
real systems and not a chance configuration of interloping galaxies. The same holds for triplets composed
by 3 red, non star-forming galaxies, showing the correlation of galaxy properties in these systems. From the
analysis of the triplet as a whole, we conclude that, at a given total stellar mass content, triplets show a total
star formation activity and global colours similar to compact groups. However, blue triplets show a high total
star formation activity with a lower stellar mass content. From an analysis of the compactness parameter of
the systems we find that light is even more concentrated in triplets than in compact groups. We propose that
triplets composed by 3 luminous galaxies, should not be considered as an analogous of galaxy pairs with an
extra member, but rather they are a natural extension of compact groups.
B
1
2
3
4
[email protected]
Instituto de Ciencias Astronómicas, de la Tierra y del Espacio (ICATE)
Consejo de Investigaciones Cientı́ficas y Técnicas (CONICET)
Departamento de Astronomia, Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas da USP
Instituto de Astronomı́a Teórica y Experimental (IATE), Observatorio Astronómico, Universidad Nacional de Córdoba
412
Posters
Galaxies
GAL -7:
#218
The galaxy-halo connection and scale relations for disks galaxies
Mancillas-Vaquera B. L.B1
In this work is used the galaxy-halo connection empirically constrained to build an updated static model
which is a generalization of Mo Mao & White model (1998), and wich obtains scale relations, dynamicstructure functions and the rotation curves decompositions of local disc galaxies population. We proceed
generating a synthetic catalog (mock catalog) with semi-empirical relations formed by millions of galaxies
with stellar masses, halo masses, color, satellites population which are in staticall agreement with observations. The aim of this work is to constrain the spin parameter of the galaxy, and to compare the structural
and dynamics properties of the synthetic catalog with observations from a sample of galaxies compiled and
adequately homogenized from literature. Thereby, applying the static model to each of galaxies in the catalog, we measure scale relations, baryonic mass-dark mass into optical radius function of mass and surface
density. Furthermore, we calculate stellar mass and velocity functions for each galaxy in the synthetic catalog.
B
1
[email protected]
Instituto de Astrofı́sica, Universidad Nacional Autónoma de México
413
Galaxies
Posters
GAL -7:
#219
Potential-Density Pairs for Thin Disks and Spheroidal Haloes II: Expansion in
Chevishev Type II Polynomials
Martı́nez, S. M.B1 ; González, G. A.; Reina, J. I.
We present an infinite family of power-density pairs for galaxy models composed by thin disks and spheroidal
haloes. In order to obtain the models, we first introduce the oblate spheroidal coordinates, which adapt in
a natural way to the geometry of the model. On crossing the disk, one of the oblate coordinates present
a change of sign without changing their absolute value, leading so to a finite discontinuity of the normal
derivative of the potential across the disk. Accordingly, we can obtain the surface mass density of the disk
by applying the Gauss law across the disk and the density of matter of the spheroidal halo by means of the
Poisson equation. The models are then obtained by expressing the gravitational potential as a superposition
of products of the Legendre functions of second class with the Chevishev Type II polynomials. Given a solution f