ON THE INTERMEDIATE-EDSHIFT CENTRAL STELLAR MASS-HALO MASS RELATION, AND IMPLICATIONS FOR THE EVOLUTION OF THE MOST MASSIVE GALAXIES SINCE z similar to 1

摘要

The stellar mass-halo mass relation is a key constraint in all semi-analytic, numerical, and semi-empirical models of galaxy formation and evolution. However, its exact shape and redshift dependence remain under debate. Several recent works support a relation in the local universe steeper than previously thought. Based on comparisons with a variety of data on massive central galaxies, we show that this steepening holds up to z similar to 1 for stellar masses M-star greater than or similar to 2 x 10(11) M-circle dot. Specifically, we find significant evidence for a high-mass end slope of beta greater than or similar to 0.35-0.70 instead of the usual beta less than or similar to 0.20-0.30 reported by a number of previous results. When including the independent constraints from the recent Baryon Oscillation Spectroscopic Survey clustering measurements, the data, independent of any systematic errors in stellar masses, tend to favor a model with a very small scatter (less than or similar to 0.15 dex) in stellar mass at fixed halo mass, in the redshift range z < 0.8 and for M-star > 3 x 10(11) M-circle dot, suggesting a close connection between massive galaxies and host halos even at relatively recent epochs. We discuss the implications of our results with respect to the evolution of the most massive galaxies since z similar to 1.