The Keck Observatory Database of Ionized Absorbers Toward QSOs (KODIAQ): II. A large Sample of CIV Selected Absorbers in the IGM and the ISM and CGM of Galaxies at z>1.6

As part of the KODIAQ program (supported through ADAP NASA grant NNX10AE84G.), we have begun a comprehensive search for metal line absorption in the spectra of 20 of the highest signal to noise spectra in the KODIAQ database. Our search selects absorption line systems based on the presence of observed absorption in triply ionized carbon (CIV). CIV is present in gas having a wide range of neutral hydrogen column density and total hydrogen density. As such, this database probes a wide range of astrophysical environments from the low density, highly ionized intergalactic medium up through the high density, mostly neutral ISM of galaxies. Our sample covers absorption over the range 1.6 < z < 4, a significant fraction of the age of the universe, and a period where significant changes in the galaxy population and the galaxy-circumgalactic medium interface take place. We present the current status of our survey and offer a preliminary interpretation of the results.