2011/04/26 by Renyue Cen · 1 citation
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Physics #Redshift #Star formation #Stellar, planetary, and galactic studies #astro-ph.CO #astro-ph.HE
paper · pdf · doi:10.1088/0004-637x/741/2/99
27 pages, 13 figures, submitted to ApJ, comments appreciated
arxiv created 2011/04/26 · openalex publication_date 2011/10/24 · arxiv updated 2015/05/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Utilizing high-resolution large-scale galaxy formation simulations of the standard cold dark matter model, we examine global trends in the evolution of galaxies due to gravitational shock heating by collapse of large halos and large-scale structure. We find two major global trends. (1) The mean specific star formation rate (sSFR) at a given galaxy mass is a monotonically increasing function with increasing redshift. (2) The mean sSFR at a given redshift is a monotonically increasing function of decreasing galaxy mass that steepens with decreasing redshift. The general dimming trend with time merely reflects the general decline of gas inflow rate with increasing time. The differential evolution of galaxies of different masses with redshift is a result of gravitational shock heating of gas due to formation of large halos (groups and clusters) and large-scale structure that moves a progressively larger fraction of galaxies and their satellites into environments where gas has too high an entropy to cool to continue feeding resident galaxies. Overdense regions where larger halos are preferentially located begin to be heated earlier and have higher temperatures than lower density regions at any given time, causing sSFR of larger galaxies to fall below the general dimming trend at higher redshift than less massive galaxies and galaxies with high sSFR to gradually shift to lower density environments at lower redshift. We find that several noted cosmic downsizing phenomena are different manifestations of these general trends. We also find that the great migration of galaxies from blue cloud to red sequence as well as color–density relation, among others, may arise naturally in this picture.