Extended galaxy halo gas through HI and OVI

The study is based on a sample of 95 galaxies from a highly complete (>80 percent) survey of faint galaxies (L>0.1L*) with archival quasar absorption spectra and 53 galaxies from the literature. A clear anticorrelation is found between HI (OVI) column density and virial radius normalized projected distance, d/Rh.

Strong HI (OVI) absorption systems with column densities greater than 10^14.0^ (10^13.5^)cm^-2^ are found for 48 of 54 (36 of 42) galaxies at d<Rh indicating a mean covering fraction of <{kappa}_HI_>=0.89 (<{kappa}_OVI_>=0.86). OVI absorbers are found at d~Rh, beyond the extent observed for lower ionization species. At d/Rh=1-3 strong HI (OVI) absorption systems are found for only 7 of 43 (5 of 34) galaxies (<{kappa}_HI_>=0.16 and <{kappa}_OVI_>=0.15).