2013/02/28 by Xiaohu Yang, H. J. Mo, Frank C. van den Bosch +5
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Cuspy halo problem #Dark matter #Dark matter halo #Galaxies: Formation, Evolution, Phenomena #Galaxy #Halo #Physics #Star (game theory) #Stellar, planetary, and galactic studies #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.1088/0004-637x/770/2/115
15 figures, 22 pages, Accepted for publication in ApJ
arxiv created 2013/05/01 · openalex publication_date 2013/06/03 · arxiv updated 2015/06/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Using the self-consistent modeling of the conditional stellar mass functions across cosmic time by Yang et al., we make model predictions for the star formation histories (SFHs) of central galaxies in halos of different masses. The model requires the following two key ingredients: (1) mass assembly histories of central and satellite galaxies and (2) local observational constraints of the star formation rates (SFRs) of central galaxies as a function of halo mass. We obtain a universal fitting formula that describes the (median) SFH of central galaxies as a function of halo mass, galaxy stellar mass, and redshift. We use this model to make predictions for various aspects of the SFRs of central galaxies across cosmic time. Our main findings are the following. (1) The specific star formation rate at high z increases rapidly with increasing redshift [∝(1 + z ) 2.5 ] for halos of a given mass and only slowly with halo mass ( ) at a given z , in almost perfect agreement with the specific mass accretion rate of dark matter halos. (2) The ratio between the SFR in the main branch progenitor and the final stellar mass of a galaxy peaks roughly at a constant value, ∼10 −9.3 h 2 yr −1 , independent of the halo mass or the final stellar mass of the galaxy. However, the redshift at which the SFR peaks increases rapidly with halo mass. (3) More than half of the stars in the present-day universe were formed in halos with 10 11.1 h −1 M ☉ < M h < 10 12.3 h −1 M ☉ in the redshift range 0.4 < z < 1.9. (4) The star formation efficiencies (SFEs) of central galaxies reveal a "downsizing" behavior, in that the halo "quenching" mass, at which the SFE peaks, shifts from ∼10 12.5 h −1 M ☉ at z ≳ 3.5 to ∼10 11.3 h −1 M ☉ at z = 0. (5) At redshift z ≳ 2.5 more than 99% of the stars in the progenitors of massive galaxies are formed in situ, and this fraction decreases as a function of redshift, becoming ∼60% at z = 0. For a Milky-Way-sized halo of M h ∼ 10 12 h −1 M ☉ more than 80% of all the stars are formed in situ, as opposed to having been accreted from satellite galaxies.