Bibcode
DOI
Tinker, Jeremy L.; Conroy, Charlie; Norberg, Peder; Patiri, Santiago G.; Weinberg, David H.; Warren, Michael S.
Bibliographical reference
The Astrophysical Journal, Volume 686, Issue 1, pp. 53-71.
Advertised on:
10
2008
Journal
Citations
108
Refereed citations
99
Description
We use measurements of the projected galaxy correlation function
wp(rp) and galaxy void statistics to test whether
the galaxy content of halos of fixed mass is systematically different in
low-density environments. We present new measurements of the void
probability function (VPF) and underdensity probability function (UPF)
from Data Release 4 of the Sloan Digital Sky Survey (SDSS), as well as
new measurements from the Two-Degree Field Galaxy Redshift Survey. We
compare these measurements to predictions calculated from models of the
halo occupation distribution (HOD) that are constrained to match both
the projected correlation function wp(rp) and the
space density of galaxies n¯g. The standard
implementation of the HOD assumes that galaxy occupation depends on halo
mass only, and is independent of local environment. For
luminosity-defined samples, we find that the standard HOD prediction is
a good match to the observations, and the data exclude models in which
galaxy formation efficiency is reduced in low-density environments. More
remarkably, we find that the void statistics of red and blue galaxies
(at L~0.4L*) are perfectly predicted by standard HOD models
matched to the correlation function of these samples, ruling out
``assembly bias'' models in which galaxy color is correlated with
large-scale environment at fixed halo mass. We conclude that the
luminosity and color of field galaxies are determined predominantly by
the mass of the halo in which they reside and have little direct
dependence on the environment in which the host halo formed. In broader
terms, our results show that the sizes and emptiness of voids found in
the distribution of L>~0.2L* galaxies are in excellent
agreement with the predictions of a standard cosmological model with a
simple connection between galaxies and dark matter halos.