Galaxy Populations in Galaxy Clusters Selected by the South Pole Telescope

Thursday, 27 August 2015 1:30 p.m. — 2 p.m. MST

AURA Lecture Hall

NOIRLab South Colloquia

The  South Pole Telescope (SPT) SZ-Survey has compiled a cluster sample of 677 (409) candidates above a signal-to-noise of 4.5 (5.0) over 2500 sq-deg. As the SZ-selection method is mass limited and nearly redshift independent, this cluster sample represents an opportunity to study the evolution of the galaxy population in a systematic fashion up to redshift ~1.5.  We present optical properties of two cluster subsamples: One sample which includes the 26 most massive galaxy clusters within the survey, and another sample of 77 clusters over a wider mass range drawn from a continuous region surveyed by the Dark Energy Survey for the science verification process. Optical properties such as the luminosity function, the Halo Occupation Number, the radial galaxy profile for all galaxies, and the red sequence populations, are analyzed.   We find a general consistency between our results and results found in the literature on samples built with different selection techniques.  Most interestingly, we find some preference for an evolution in the faint end slope of the Schechter function as well as the NFW concentration, when the red-sequence galaxy population is studied.