Download DETAILED STELLAR POPULATION ANALYSIS OF GALAXY

DETAILED
STELLAR
POPULATION
ANALYSIS
OF
GALAXY
CLUSTERS
AT
INCREASING
READSHIFT:
a
constrain
for
their
evolution
Anna
Ferré‐Mateu(1),
P.
Sánchez‐Blázquez(2),
A.
Vazdekis(1),
I.G.
de
la
Rosa(1),
R.
Davies(3),
R.
Masters(3),
R.
Houghton(3),
a.
Beifiori(3)
Instituto
de
Astrofísica
de
Canarias(1);
Universidad
Autónoma
de
Madrid(2),
University
of
Oxford(3)
ABSTRACT:
The
poster
describe
a
project
of
a
detailed
stellar
population
analysis
for
different
clusters
of
galaxies
with
increasing
redshift.
The
selected
clusters
are
part
of
the
GEMINI/HST
Galaxy
Cluster
Project
(PIs
I.
Jorgensen
&
R.
Davies.
For the Gemini/HST Galaxy Cluster Project, a sample of 15 galaxy clusters with redshifts between 0.2 and 1
were chosen based on their X-ray luminosities. The sample is limited to clusters with X-ray luminosities larger than LX = 2 × 1044 ergs per second and is intended to be
representative of rich galaxy clusters. The galaxies for which spectra were obtained can be several times less luminous than the Milky Way. GMOS spectra and HST imaging
are available for all of them. The high S/N of the spectra allow us to analyse the stellar population of individual galaxies, allowing us to study trends with morphological type,
or distance to the center of the cluster.
In
this
poster,
we
present
very
preliminary
analysis
for
two
different
clusters
of
this
sample,
the
RX
J0152.7‐1357
(z=0.83)
and
the
MS0451
(z=0.57),
intended
to
show
the
different
techniques
we
are
planning
to
apply
in
this
study.
8
z=0.
METHODOLOGY:
We
will
perform
different
stellar
population
analysis
techniques.
3
DATA
QUALITY:
Galaxy
spectra
have
a
very
high
S/N
ratio
(see
some
examples
for
galaxies
in
the
two
clusters),
which
allow
us
to
perform
stellar
population
analysis
in
individual
galaxies.
Both
clusters
are
flux‐
calibrated
and
the
telluric
lines
were
removed.
 LINE
STRENGTHS:
Line‐strength
indices
were
measured
and
compared
with
the
new
Vazdekis
stellar
population
models
(Vazdekis
et
al.,
2010)
and
the
routine
RMODEL
(Cardiel,
03),
which
derives
ages
and
metalicities
for
each
galaxy.
 FULL
SPECTRAL
FITTNG:
several
techniques
for
the
full
spectral
fitting
will
be
compared
by
deriving
ages
and
metalicities
on
the
same
range
for
all
the
spectra.
We
will
use
ULYSS
(Koleva
et
al.
09),
STARLIGHT
(Cid‐Fernandes
et
al.
05)
and
STECKMAP
(Ocvirk
et
al.
2006)
 KINEMATICS:
The
sigma
values
and
radial
velocities
were
derived
by
means
of
the
Penalized
Pixel‐Fitting
method
PPXF
(Capellari
&
Emsellem,
04).
However,
the
obtained
values
are
compared
with
the
values
obtained
with
the
different
spectral
fitting
techniques.
We
use
GANDALF
(Sarzi
et
al.
06)
to
fit
the
emission
lines
in
the
spectra
before
applying
ppxf.
57
z=0.
FULL
SPECTRAL
FITTING:
Upper
panel:
fit
performed
with
with
ULYSS
(Koleva,
09).
Bottom
panel:
same
with
STARLIGHT
(Cid‐
Fernandes,
05)
http://miles.iac.es
σ< 150 kms
150<σ<275 km/s
σ>275 km/s
LINE
STRENGHTS.
Open
squares:
cluster
at
z=0.83;
Full
circles
correspond
to
the
z=0.57
one.
★ z=0.57
# z=0.83
− −# Evolution if passive evolution
KINEMATICS:
PPXF
(Capellari
&
Emsellem,
04)
&
GANDALF
(Sarzi
et
al.
06)
MAIN
GOALS:
We
consider
three
different
redshift
bins:
low‐z
(z<0.4),
mid‐z
(0.4<z<0.7)
and
high‐z
(z>0.7),
which
allow
us
to
constrain
the
galaxy
evolution
by
studying
the
stellar
populations
in
early‐type
galaxies
on
an
individual
basis.
For
all
clusters,
the
objectives
are:
 Study
of
the
stellar
populations
by
means
of
line‐strengths
and
their
relations
with
sigma
 Study of the stellar populations by means of full spectral fitting
 The
study
of
the
true
nature
of
Ellipticals
vs
S0
 Study of the Fundamental Plane
 The
environmental
dependence
Keepd
 Jeans
modeling
 ….
Tune
CONTACT:
[email protected]