Found 89 talks width keyword galaxy evolution

Thursday March 12, 2009

Large scale structures and galaxy evolution in the COSMOS Survey

California Institute of Technology, USA

Archived in: Cosmology, Catalogs and data - Keywords:galaxy evolution, large-scale structure, dark matter, COSMOS

Abstract

Wednesday January 28, 2009

The large scale inhomogeneity of the galaxy distribution

Institute for Complex Systems, CNR, Italy

Archived in: Galaxies, Cosmology - Keywords:n-body simulations, galaxy evolution, galactic formation, large-scale structure, SDSS, 2dF

Abstract

Thursday January 22, 2009

Dark matter in early-type galaxies: a SAURON view

Leiden Observatory, the Netherlands

Archived in: Galaxies - Keywords:galactic kinematics , galactic formation, galactic dynamics, early-type galaxies, dark matter, galaxy evolution, SAURON

Abstract

Tuesday November 25, 2008

The star formation history of different types of dwarf galaxies

Instituto de Astrofísica de Canarias, Spain

Archived in: - Keywords:star formation, M33, galaxy evolution, galactic formation, dwarf galaxies

Abstract

Monday November 17, 2008

Globular clusters systems and their host dark matter halos

Swinburne University, Australia

Archived in: Particle astrophysics, physical data and processes, Galaxies, Stars - Keywords:globular clusters, star formation, gravitational lensing, star clusters, galaxy evolution, galactic formation, galactic abundances, dark matter

Abstract

Thursday November 13, 2008

The (very) small-scale structure of dark matter halos

Max-Planck Institut für Astrophysik, Garching, Germany

Archived in: Cosmology, Computing - Keywords:distance scale, dark matter, GLAST, galactic formation, galactic halos, galaxy evolution, fundamental physics, numerical simulations

Abstract

Friday October 24, 2008

(1) Stellar kinematics in double-barred galaxies: the sigma-hollows (2) A colorful view on the outskirt of spiral galaxies: clues on disk-formation scenarios

Instituto de Astrofísica de Canarias, Spain

Abstract

(1) We present SAURON integral-field stellar velocity and velocity dispersion maps for four double-barred early-type galaxies: NGC2859, NGC3941,NGC4725 and NGC5850. The presence of the nuclear bar is not evident from the radial velocity, but it appears to have an important effect in the stellar velocity dispersion maps: we find two sigma-hollows of amplitudes between 10 and 40 km/s at either sides of the center, at the ends of the nuclear bars. We have performed numerical simulations to explain these features. Ruling out other possibilities, we finally conclude that, although the sigma-hollows may be originated by a younger stellar population component with low velocity dispersion, more likely they are an effect of the contrast between two kinematically different components: the high velocity dispersion of the bulge and the ordered motion (low velocity dispersion) of the nuclear bar.

(2) We have explored radial color and stellar surface mass density profiles for a sample of 85 late-type galaxies with available deep (down to ~27.0 mag/arcsec² SDSS g'- and r'-band surface brightness profiles. About 90% of the light profiles have been classified as broken exponentials, exhibiting either truncations (Type II galaxies) or antitruncations (Type III galaxies). Their associated color profiles show significantly different behavior. For the truncated galaxies a radial inside-out bluing reaches a minimum of (g' - r') = 0.47 +/- 0.02 mag at the position of the break radius, this is followed by a reddening outwards. The anti-truncated galaxies reveal a more complex behavior: at the break position (calculated from the light profiles) the color profile reaches a plateau region - preceded with a reddening - with a mean color of about (g' - r') = 0.57 +/- 0.02 mag. Using the color to calculate the stellar surface mass density profiles reveals a surprising result. The breaks, well established in the light profiles of the Type II galaxies, are almost gone, and the mass profiles resemble now those of the pure exponential Type I galaxies. This result suggests that the origin of the break in Type II galaxies are most likely to be a radial change in stellar population, rather than being caused by an actual drop in the distribution of mass. The anti-truncated galaxies on the other hand preserve their shape to some extent in the stellar surface mass density profiles. We find that the stellar surface mass density at the break for truncated (Type II) galaxies is 13.6 +/- 1.6 Msun/pc² and 9.9 +/- 1.3 Msun/pc² for the anti-truncated (Type III) ones. We estimate that ~15% of the total stellar mass in case of Type II galaxies and ~9% in case of Type III galaxies are to be found beyond the measured break radii.

Archived in: Galaxies - Keywords:galactic kinematics , galactic dynamics, galactic bulges, galactic bars, early-type galaxies, galaxy evolution, late-type galaxies, spiral galaxies, star forming galaxies, abundances, stellar populations

Abstract

Thursday July 24, 2008

Properties of the dwarf galaxy population in galaxy clusters

Instituto de Astrofísica de Canarias, Spain

Archived in: Galaxies - Keywords:galactic clusters, dwarf galaxies, SDSS, galaxy evolution

Abstract

Thursday May 22, 2008

(1) Stellar disks in the intermediate redshift range: listening to the galaxy evolution "Symphony". (2) Unveiling the narrow-line Seyfert 1 nature of Mrk 573 using near-infrared spectroscopy

Instituto de Estructura de la Materia, CSIC, Spain
University of Sheffield, UK

Abstract

1) In this brief seminar (<~25 minutes+questions) I will present recent results on the study of "deep", high resolution, surface brightness profiles of a sample of ~500 late-type galaxies in the redshift range 0.1—1.1, making use of publicly available HST/ACS imaging of the GOODS-South field. We have classified and parameterized, according to usual prescriptions in this kind of analysis, these profiles, with special emphasis put on the so called ``truncated'' disks. This is the case in which, beyond a certain radius, termed as ``Break Radius'', the exponentially decaying surface brightness profile along the stellar disk gives way to an even more abrupt exponential decay. This radius can be taken as an spatial "scale" for the disk, as observed in a given band (in our case, the rest-frame B-band). Comparing with analogous analysis for galaxies in the Local Universe, as we have done, it is possible to extract valuable information on the evolution of several photometric properties of the stellar disks of galaxies, related to the stellar populations distributions. I will also present results on the analysis of the color profiles of this sample of galaxies, which have yield an interesting result which is, perhaps, the main reason that justifies calling this talk a "breaking news" seminar, as I will show. Summarizing, an overview of the results we have obtained will be given, and our conclusions on them, explaining how they can be understood in the frame of Galaxy Evolution (2) Based on high quality near-infrared spectroscopy (obtained with WHT/LIRIS) we reveal that the nucleus of Mrk 573 is an obscured Narrow-Line Seyfert 1 and not an archetypal Seyfert 2 as it has been classified until now. Currently only four AGNs have been classified into this category. We have detected permitted OI and FeII transitions, which indicates the existence of a high density region similar to the BLRs detected in type 1 AGN.

Archived in: Galaxies, Catalogs and data - Keywords:supermassive black hole, SMBH, Seyfert galaxies, Mrk 573, galaxy evolution, galactic kinematics

Abstract