X-Ray luminosities for ~41000 AGNs

We selected all optically detected SDSS sources with redshift measurements, combined additional broadband photometry from WISE, UKIDSS, 2MASS, and GALEX, and modeled the spectral energy distributions (SEDs) of our sample sources. We parameterize nuclear obscuration in our SEDs with E(B-V)_AGN_ and uncover thousands of powerful obscured AGNs that lack X-ray counterparts, many of which are identified as AGN candidates based on straightforward WISE photometric criteria.

Using the observed luminosity correlation between rest-frame 2-10 keV (L_X_) and rest-frame AGN 6um (L_MIR_), we estimate the intrinsic X-ray luminosities of our sample sources and combine these data with flux limits from X-ray catalogs to determine lower limits on nuclear obscuration. Using the ratio of intrinsic-to-observed X-ray luminosity (R_L_X__), we find a significant fraction of sources with column densities approaching N_H_>10^24^/cm^2^, suggesting that multiwavelength observations are necessary to account for the population of heavily obscured AGNs.