DECam Community Science Workshop 2018: Science Highlights, Coming Opportunities, LSST Synergies
May 21-22, 2018 • Tucson, Arizona
Stellar Mass Growth of Massive Central Galaxies [13.37 MB PDF]
Massive galaxies, the most massive of which are generally found at the centers of the largest dark matter halos in the universe, provide a unique laboratory for investigating several longstanding problems in galaxy formation and evolution. Despite their importance, however, measurements of the mass assembly and star formation histories of massive galaxies remain discordant and controversial, resulting in significant uncertainties in how numerical simulations treat gas cooling, star formation, and feedback from supernovae and supermassive black holes in massive halos. To address these issues, we have measured accurate integrated stellar masses of more than 50,000 massive central galaxies at z<0.5 using new deep, wide-area optical and mid-infrared imaging from the Legacy Surveys (legacysurvey.org). We find a non negligible reservoir of stellar mass in the low surface-brightness outer envelopes of the central galaxies in our sample, which has wide-ranging implications for inferences of the efficiency of star formation and the intensity of AGN feedback in massive dark matter halos.
Authors: John Moustakas, Dustin Lang, Arjun Dey, Eduardo Rozo, Eli Rykoff, David Schlegel, & Risa Wechsler