maximum likelihood fitting of tidal streams with application
... star counts often suggested a more spherical spheroid (Bahcall 1986). By early in the 21st century, the spheroid was still thought of as a smooth power-law distribution, but studies were starting to show that the shape of the spheroid depended on the type of star being observed, and it was noted tha ...
... star counts often suggested a more spherical spheroid (Bahcall 1986). By early in the 21st century, the spheroid was still thought of as a smooth power-law distribution, but studies were starting to show that the shape of the spheroid depended on the type of star being observed, and it was noted tha ...
Carbon, nitrogen and oxygen abundances in
... stars are selected according to their effective temperatures Teff and surface gravities log g, namely: Teff is between 15 300 and 24 100 K and log g is mostly greater than 3.75; therefore, stars with medium masses of 5–11 M are selected. Theory predicts for the stars with such parameters that the C ...
... stars are selected according to their effective temperatures Teff and surface gravities log g, namely: Teff is between 15 300 and 24 100 K and log g is mostly greater than 3.75; therefore, stars with medium masses of 5–11 M are selected. Theory predicts for the stars with such parameters that the C ...
Annual Report 2012
... television on ALMA, with Leiden astronomers Ewine van Dishoeck and Tim van Kempen. Rumour has it that as a special tribute to Leiden it was broadcast on October 3. A fascinating project that combines outreach, techniques developed for astronomy and citizen science is ISPEX. ISPEX is a small device t ...
... television on ALMA, with Leiden astronomers Ewine van Dishoeck and Tim van Kempen. Rumour has it that as a special tribute to Leiden it was broadcast on October 3. A fascinating project that combines outreach, techniques developed for astronomy and citizen science is ISPEX. ISPEX is a small device t ...
The old globular cluster system of the dIrr galaxy NGC 1427A in the
... In all these models, the GCSs of low-mass dwarf galaxies, the most numerous galaxy type in galaxy clusters (Sandage 2005, and references therein), are envisioned as the building blocks of the GCSs of the more massive galaxies. At present the role of the GCSs of dIrr galaxies in the frame of galaxy f ...
... In all these models, the GCSs of low-mass dwarf galaxies, the most numerous galaxy type in galaxy clusters (Sandage 2005, and references therein), are envisioned as the building blocks of the GCSs of the more massive galaxies. At present the role of the GCSs of dIrr galaxies in the frame of galaxy f ...
Massive Disruptions in the Cool Core of MACS J1931.8-2634 Steven Ehlert
... Snowcluster March 31st 2010 ...
... Snowcluster March 31st 2010 ...
Absorption of high-energy gamma rays in Cygnus X-3
... 1993; Bednarek 2010). Some Wolf-Rayet stars present an excess in soft X-rays with luminosities up to ∼1033 erg s−1 , particularly in nitrogen-rich stars (e.g. Skinner et al. 2010). This source of photons would be negligible in Cygnus X-3 where the X-ray luminosity is about 1038 erg s−1 , and will no ...
... 1993; Bednarek 2010). Some Wolf-Rayet stars present an excess in soft X-rays with luminosities up to ∼1033 erg s−1 , particularly in nitrogen-rich stars (e.g. Skinner et al. 2010). This source of photons would be negligible in Cygnus X-3 where the X-ray luminosity is about 1038 erg s−1 , and will no ...
The nature of extremely red galaxies in the local universe
... RS. Why are these galaxies so red? Is this due to old, probably metal-rich stars? Is this due to dust? Indeed, dust in the interstellar medium of galaxies, besides absorbing part of the optical light, may redden galaxy colours. There is, actually, an age–extinction degeneracy: a galaxy possessing hi ...
... RS. Why are these galaxies so red? Is this due to old, probably metal-rich stars? Is this due to dust? Indeed, dust in the interstellar medium of galaxies, besides absorbing part of the optical light, may redden galaxy colours. There is, actually, an age–extinction degeneracy: a galaxy possessing hi ...
Moving mesh cosmology: numerical techniques and global statistics
... 2011), cosmic ray physics (Jubelgas et al. 2008), thermal conduction (Dolag et al. 2004; Jubelgas, Springel & Dolag 2004) or black hole physics (Di Matteo, Springel & Hernquist 2005; Springel et al. 2005a; Di Matteo et al. 2008). Hydrodynamical simulations have been successfully used to study the Ly ...
... 2011), cosmic ray physics (Jubelgas et al. 2008), thermal conduction (Dolag et al. 2004; Jubelgas, Springel & Dolag 2004) or black hole physics (Di Matteo, Springel & Hernquist 2005; Springel et al. 2005a; Di Matteo et al. 2008). Hydrodynamical simulations have been successfully used to study the Ly ...
10:30 Coffee break - Astrometry and Astrophysics in the Gaia sky
... 17:00 Rachael Beaton The Carnegie-Chicago Hubble Program, A Population-II Distance Ladder 17:20 Jean Souchay The LQAC-4, last update of a the Large Quasar Astrometric Catalogue 17:40 Christopher Jacobs Tying multiple Radio Wavelength Celestial Frames to the Gaia Optical Frame 18:00 Tobias Fritz Usin ...
... 17:00 Rachael Beaton The Carnegie-Chicago Hubble Program, A Population-II Distance Ladder 17:20 Jean Souchay The LQAC-4, last update of a the Large Quasar Astrometric Catalogue 17:40 Christopher Jacobs Tying multiple Radio Wavelength Celestial Frames to the Gaia Optical Frame 18:00 Tobias Fritz Usin ...
Population effects on the red giant clump absolute magnitude, and
... A subtle one is that M RC is assumed either not to depend on I ages (as in Udalski 1998a, 2000), or not to depend on metallicities (as in Udalski 1998b). Thus, the presence of an age±metallicity relation (AMR) in the observational data could be masking a on both parameters, provided that possible de ...
... A subtle one is that M RC is assumed either not to depend on I ages (as in Udalski 1998a, 2000), or not to depend on metallicities (as in Udalski 1998b). Thus, the presence of an age±metallicity relation (AMR) in the observational data could be masking a on both parameters, provided that possible de ...
Giant star seismology
... between cycle 23 and 24 are still subject of discussion (Basu et al, 2012; Basu, 2013; Jiang et al, 2015). Furthermore, oscillations sensitive to the activity suggest the presence of a 2-yr cycle in addition to the 11-yr cycle (Broomhall et al, 2012) which is yet to be understood. The road to the de ...
... between cycle 23 and 24 are still subject of discussion (Basu et al, 2012; Basu, 2013; Jiang et al, 2015). Furthermore, oscillations sensitive to the activity suggest the presence of a 2-yr cycle in addition to the 11-yr cycle (Broomhall et al, 2012) which is yet to be understood. The road to the de ...
Gravitational Waves from 3D MHD Core
... these two points, I show that it is generally very difficult to discern the effects of the individual features of the input physics in a GW signal from a rotating CCSN that can be attributed unambiguously to a specific model. Weak magnetic fields do not notably influence the dynamical evolution of t ...
... these two points, I show that it is generally very difficult to discern the effects of the individual features of the input physics in a GW signal from a rotating CCSN that can be attributed unambiguously to a specific model. Weak magnetic fields do not notably influence the dynamical evolution of t ...
2 The Concept of “Spectral Classes”
... groups of like stars without making explicit searches by star name one at a time or by cross correlation of established catalogs. In fact, this is one of the most common requests the Multi-Mission Archive at the Space Telescope Science Institute (MAST) receives. The IUE satellite project, with the F ...
... groups of like stars without making explicit searches by star name one at a time or by cross correlation of established catalogs. In fact, this is one of the most common requests the Multi-Mission Archive at the Space Telescope Science Institute (MAST) receives. The IUE satellite project, with the F ...
First DENIS I-band extragalactic catalog
... Abstract. This paper presents the first I-band photometric catalog of the brightest galaxies extracted from the Deep Near Infrared Survey of the Southern Sky (DENIS) An automatic galaxy recognition program has been developed to build this provisional catalog. The method is based on a discriminating ...
... Abstract. This paper presents the first I-band photometric catalog of the brightest galaxies extracted from the Deep Near Infrared Survey of the Southern Sky (DENIS) An automatic galaxy recognition program has been developed to build this provisional catalog. The method is based on a discriminating ...
Dust in historical Galactic Type Ia supernova remnants with Herschel
... (BLAST) and the Herschel Space Observatory showed it was difficult to distinguish between cold dust in the remnant and cold dust from intervening interstellar clouds using photometry alone (Barlow et al. 2010; Sibthorpe et al. 2010). These studies revealed a new cool component of dust in Cas A with ...
... (BLAST) and the Herschel Space Observatory showed it was difficult to distinguish between cold dust in the remnant and cold dust from intervening interstellar clouds using photometry alone (Barlow et al. 2010; Sibthorpe et al. 2010). These studies revealed a new cool component of dust in Cas A with ...
Star formation
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as ""stellar nurseries"" or ""star-forming regions"", collapse to form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.