A survey of hard X-ray emitting AGN selected by the Chandra Multiwavelength Project

J. Silverman

We present X-ray and optical analysis of 188 AGN identified from hard (2-8 keV) X-ray sources in 20 Chandra fields forming part of the Chandra Multiwavelength Project. These medium depth X-ray observations enable us to detect a representative subset of those sources responsible for the bulk of the Cosmic X-ray background. We find that most X-ray unabsorbed AGN (log NH<22) have optical properties characterized by broad emission lines and blue colors, similar to optically-selected quasars from the Sloan Digital Sky Survey but with a slightly broader color distribution. However, we also find a significant population of redder (g'-i'>1) AGN with broad optical emission lines. Most of the X-ray absorbed AGN (log NH>22) are associated with narrow emission line galaxies, with red optical colors characteristically dominated by luminous, early type galaxies, rather than from dust reddening of an AGN. Overall, we find that 81% of X-ray selected AGN can be easily interpreted in the context of current AGN unification models. Most of the deviations seem to be due to an optical contribution from the host galaxies of the low luminosity AGN.