The Galaxy Environment of O VI Absorption Systems

We combine a FUSE sample of O VI absorbers (z < 0.15) with a database of 1.07 million galaxy redshifts to explore the relationship between absorbers and galaxy environments. All 37 absorbers with N(O VI) . 10(13.2) cm(-2) lie within 800 h(70(-1) kpc of the nearest galaxy, with no compelling evidence for O VI absorbers in voids. The O VI absorbers often appear to be associated with environments of individual galaxies. Gas with 10% c 5% solar metallicity (O VI and C III) has a median spread in distance of 350-500 h(70(-1) kpc around L(*) galaxies and 200-270 h(70(-1) kpc around 0.1 L(*) galaxies (ranges reflect uncertain metallicities of gas undetected in Lya absorption). In order to match the O VI line frequency, (dN/dz) - 20 for N(O VI) 10(13.2) cm(-2), galaxies with L , 0.1L(*) must contribute to the cross section. Lya absorbers with N(H I) . 10(13.2) cm(-2) cover 650% of the surface area of typical galaxy filaments. Two-thirds of these show O VI and/or C III absorption, corresponding to a 33%-50% covering factor at 0.1 Z(z) and suggesting that metals are spread to a maximum distance of 800 h(70(-1) kpc, within typical galaxy supercluster filaments. Approximately 50% of the O VI absorbers have associated Lya line pairs with separations (\)(Lya) = 50-200 km s(-1). These pairs could represent shocks at the speeds necessary to create copious O VI, located within 100 h(70(-1) kpc of the nearest galaxy and accounting for much of the two-point correlation function of low-z Lya forest absorbers.