We use observations from the 9 square degree multiwavelength survey in Boötes to identify hundreds of obscured active galactic nuclei ( AGN ) with high redshifts ( z > 0.7 ) , luminosities ( L _ { bol } > 10 ^ { 45 } ergs s ^ { -1 } ) , and moderate obscuring columns ( N _ { H } > 10 ^ { 22 } cm ^ { -2 } ) , and to measure the clustering properties of X-ray AGN at z > 1 .
In the Boötes region , shallow ( 5 ks ) Chandra X-ray observations have detected \sim 4,000 X-ray sources , and the same region has been mapped with deep optical imaging and by Spitzer IRAC , which detects \sim 300,000 point sources , of which \sim 30,000 have detections in all four IRAC bands , for which we can select AGN on the basis of their mid-IR colors .
With the MMT/Hectospec we have obtained modest resolution optical spectra for about half the X-ray sources ( out to z > 3 ) and \sim 20,000 galaxies ( out to z = 0.7 ) .
With this multiwavelength data we select > 400 AGN per square degree ( compared to 12 per square degree from SDSS ) .
Among a sample of IRAC-selected AGN we identify 641 candidate obscured objects based on their R band and IRAC luminosities .
We use X-ray stacking techniques to verify that they are obscured AGN and measure their absorbing column densities .
We also measure the three-dimensional two-point correlation function for X-ray selected AGN .