case western reserve university



The Growth of Dead Galaxies in Clusters over Most of Cosmic Time

Greg Rudnick (Kansas)

Abstract: Tracking the growth of stellar mass in galaxies is a fundamental characterization of the galaxy population. Recent observations have shown that the total mass in L>L* red galaxies has increased by a factor of ~2 at z<1, although at different rates as a function of galaxy mass. Despite the advance made by these studies of the whole galaxy population, until recently it has not been clear if the growth of the red sequence depended on environment. Galaxy clusters are a useful probe of this as they sample the most extreme environments. I will show how the luminosity function (LF) of red-sequence galaxies in clusters and the field has evolved over 50% of cosmic time, highlighting the rapid buildup of the faint cluster galaxy population. I will address how the total mass on the red sequence evolves in clusters and will use this to constrain the mechanisms of how red galaxies can be added to clusters. From this analysis it appears likely that some fraction of the light in recently added cluster red sequence galaxies is currently in the in the form of intracluster stars. Finally, I will show some new results focusing on a newly discovered cluster at z=1.62.