The Keck Observatory Database of Ionized Absorbers toward QSOs (KODIAQ): Hunting for OVI Absorbers at z>2 to Probe the Physics and Metal Budget of the Circumgalactic Medium

Exploring the circumgalactic medium (CGM) between galaxies and the intergalactic medium is critical to our understanding of the formation and evolution of structures in the universe. OVI is a key tracer of the flows in the CGM. We have undertaken a large research program with the Keck Observatory Archive (KOA) to produce a comprehensive analysis of OVI (and other high and low ions) associated with optically thick absorbers (Lyman Limit systems -LLS, damped Lyα absorbers - DLA) seen in QSO spectra at z>2 observed by Keck/HIRES. Our early results imply that the O VI-bearing gas associated with LLS and DLA is a significant reservoir of baryons and metals at high z. I will present and discuss these new and exciting developments from our ADAP research program supported through NASA grant NNX10AE84G.