Heavily-obscured AGNs in the XMM-SERVS fields

We perform X-ray spectral analyses to derive the characteristics (e.g., column density, X-ray luminosity) of ~10200 active galactic nuclei (AGNs) in the XMM-Spitzer Extragalactic Representative Volume Survey, which was designed to investigate the growth of supermassive black holes across a wide dynamic range of cosmic environments. Using physical torus models (e.g., Borus02) and a Bayesian approach, we uncover 22 representative Compton-thick (CT; N_H_>1.5x10^24^cm^-2^) AGN candidates with good signal-to-noise ratios as well as a large sample of 136 heavily obscured AGNs.

We also find an increasing CT fraction (f_CT_) from low (z<0.75) to high (z>0.75) redshift. Our CT candidates tend to show hard X-ray spectral shapes and dust extinction in their spectral energy distribution fits, which may shed light on the connection between AGN obscuration and host-galaxy evolution.