Special Seminar

Speaker: Tomer Tal (Yale)
Title: Evolution of the most massive galaxies: a statistical study of SDSS LRGs
Date (JST): Thu, Feb 16, 2012, 14:00 - 15:00
Place: Balcony B
Related File: 634.pdf
Abstract: Massive galaxies in the nearby universe have very little cold gas, they host old stellar populations and exhibit extremely low specific star formation rates. Studies of these galaxies typically find that essentially all of the stellar mass growth takes place through mergers and other gravitational interactions, with the relative importance of each process still debatable. Significant efforts have been devoted to studying galaxies at high and low redshift to better understand how the most massive galaxies evolve. In this talk I will present results from a statistical analysis of the properties and satellite galaxies of Luminous Red Galaxies out to z=0.7 from SDSS and BOSS. I will show that the broadband colors of the extreme outskirts of LRGs are consistent with minor mergers as the main mode of size growth. I will also discuss how the average luminosity function of satellite galaxies around LRGs suggests that major mergers are an unlikely contributor to their growth. Lastly, I will show that the radial distribution of the same satellite galaixes is consistent with a significant baryonic contribution to the total mass profile of LRG groups at small radii.