The RESOLVE Survey Atomic Gas Census and Environmental Influences on
  Galaxy Gas Reservoirs
  We present the HI mass inventory for the RESOLVE survey, a volume-limited,
multi-wavelength census of >1500 z=0 galaxies spanning diverse environments and
complete in baryonic mass down to dwarfs of 10^9 Msun. This first 21cm data
release provides robust detections or strong upper limits (1.4M_HI < 5 to 10%
of stellar mass M_stars) for 94% of RESOLVE. We examine global atomic
gas-to-stellar mass ratios (G/S) in relation to galaxy environment using
several metrics: group dark matter halo mass M_h , central/satellite
designation, relative mass density of the cosmic web, and distance to nearest
massive group. We find that at fixed M_stars, satellites have decreasing G/S
with increasing M_h starting clearly at M_h = 10^12 Msun, suggesting the
presence of starvation and/or stripping mechanisms associated with halo gas
heating in intermediate-mass groups. The analogous relationship for centrals is
uncertain because halo abundance matching builds in relationships between
central G/S, stellar mass, and halo mass, which depend on the integrated group
property used as a proxy for halo mass (stellar or baryonic mass). On larger
scales G/S trends are less sensitive to the abundance matching method. At fixed
M_h < 10^12 Msun, the fraction of gas-poor centrals increases with large-scale
structure density. In overdense regions, we identify a rare population of
gas-poor centrals in low-mass (M_h < 10^11.4 Msun) halos primarily located
within 1.5 times the virial radius of more massive (M_h > 10^12 Msun) halos,
suggesting that gas stripping and/or starvation may be induced by interactions
with larger halos or the surrounding cosmic web. We find that the detailed
relationship between G/S and environment varies when we examine different
subvolumes of RESOLVE independently, which we suggest may be a signature of
assembly bias.
