Zhankui Lu, Houjun Mo, Yu Lu, Neal Katz, Martin Weinberg, Frank van den Bosch, Xiaohu Yang
We infer the star formation rates in dark matter halos at different redshifts from the observed stellar mass functions of galaxies at different redshifts and the luminosity function of local cluster galaxies. By parametrising the star formation as a function that is explicitly dependent on halo mass and redshift, a series of nested model families with increasing complexity are explored to understand how the structure of this function is constrained by the different data sets. To match the observed stellar mass functions at different redshifts, the star formation in the central galaxies of halos with masses above $10^{12}\Msunh$ has to be boosted at high redshift beyond what is expected from a simple scaling of the dynamical time. To reproduce the faint end of the cluster galaxy luminosity function ($M_{z}-5\log_{10}(h) > -18$) and the low mass end of the local stellar mass function simultaneously, there is a characteristic redshift $z_c \approx 2$ that defines a transition in star formation efficiency (star formation rate divided by the mean baryon mass accretion rate) in low mass halos ($<10^{11}\Msunh$). The star formation efficiency is about 1/10 at $z>z_c$ and is strongly quenched at lower $z$. This gives rises to a significant amount of old stellar population in present-day dwarf galaxies below $10^{8}\Msunhh$ and steepened slopes of the high redshift stellar mass functions and star formation rate functions, both consistent with latest observations. We use our constrained models to make predictions for the star formation and assembly histories of galaxies in halos of different masses, and for a number of properties of the galaxy population.
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http://arxiv.org/abs/1306.0650
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