Galaxy evolution from halo occupation distribution modeling of DEEP2 and SDSS galaxy clustering

We model the luminosity-dependent projected two-point correlation function of DEEP2 ( z similar to 1) and SDSS ( z similar to 0) galaxies within the HOD framework. At both epochs, there is a tight correlation between central galaxy luminosity and halo mass, with the slope and scatter decreasing for larger halo masses, and the fraction of satellite galaxies decreases at higher luminosity. We find little evolution in the relation between mass scales of host halos for central galaxies and satellite galaxies above the same luminosity threshold. Combining these HOD results with theoretical predictions of the typical growth of halos, we establish an evolutionary connection between the galaxy populations at the two redshifts by linking z similar to 0 central galaxies to z similar to 1 central galaxies that reside in their progenitor halos. We find that the stellar mass growth of galaxies depends on halo mass. On average, the majority of the stellar mass in central galaxies residing in z similar to 0 low-mass halos (similar to 5 x 10(11) h(-1) M-circle dot) and only a small fraction of the stellar mass in central galaxies of high-mass halos (similar to 10(13) h(-1) M-circle dot) result from star formation between z similar to 1 and z similar to 0. In addition, the mass scale of halos where the star formation efficiency reaches a maximum is found to shift toward lower mass with time. Future work that combines HOD modeling of the clustering of galaxies at different redshifts with the assembly history and dynamical evolution of dark matter halos can lead to an understanding of the stellar mass growth due to both mergers and star formation as a function of host halo mass and provide powerful tests of galaxy formation theories.