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We examine to what extent disk and outflow models can reproduce observations of H I gas within a few virial radii of galaxies in pairs and groups. Using highly-sensitive HST/COS and FOS spectra of the Q0107 quasar triplet covering Ly$\alpha$ for z$\lesssim$1, as well as a deep galaxy redshift survey including VIMOS, DEIMOS, GMOS and MUSE data, we test simple disk and outflow models against the H I absorption along three lines-of-sight (separated by 200-500 kpc) through nine galaxy groups in this field. These can be compared with our previous results in which these models can often be fit to the absorption around isolated galaxies. Our models can reproduce $\approx$ 75$\%$ of the 28 identified absorption components within 500 km/s of a group galaxy, so most of the H I around groups is consistent with a superposition of the CGM of the individual galaxies. Gas stripped in interactions between galaxies may be a plausible explanation for some of the remaining absorption, but neither the galaxy images nor the galaxy and absorber kinematics provide clear evidence of such stripped material, and these unexplained absorbers do not preferentially occur around close pairs of galaxies. We find H I column densities typically higher than at similar impact parameters around isolated galaxies ($\approx$ 2.5$\sigma$), as well as more frequent detections of O VI than around isolated galaxies (30$\%$ of sightlines to 7$\%$)., Comment: 33 pages, 15 figures (main text 22 pages, 9 figures). Accepted for publication in MNRAS

The cosmic diffuse X-ray background radiation has been almost completely resolved into point sources by Chandra and XMM. However, the nature and evolution of those sources are just beginning to be investigated. The answers are key to our understanding of the inter-relationship over cosmic time of (a) the formation and growth of black holes, (b) star formation, and (c) hierarchical structure formation. This requires multiwavelength followup of Chandra sources over a large area. The Chandra Multiwavelength Project (ChaMP) is a serendipitous survey of the X-ray sky, covering about 14 deg2 of sky in the X-ray flux range of -13 to -16 (log 0.5-2 keV flux, cgs) and will include about 8000 sources, 70% of which are expected to be active galactic nuclei (AGN). Using Chandra archival data, we span flux limits between those reached by previous satellites and those of the deepest small-area Chandra and XMM surveys, allowing study of larger samples of rare objects like luminous absorbed AGN, groups and clusters of galaxies, and their spatial correlations. Optical imaging and spectroscopy of the ChaMP fields are underway at a variety of telescopes using Sloan g′, r′, and i′ filters to a flux limit matched to the X-ray such that about 75% of the X-ray sources will be optically identified.We also plan for radio and near-IR observations of subsets of the ChaMP sample to expand our multi-wavelength coverage and increase the fraction of sources identified.

We measure the gas-phase oxygen abundances of ~3000 star-forming galaxies at z=0.05-0.75 using optical spectrophotometry from the AGN and Galaxy Evolution Survey (AGES), a spectroscopic survey of I_AB, 38 pages, 22 figures, 6 tables, submitted to ApJ