Heavily-Obscured AGNs and the Host Galaxies in the LSST Deep-Drilling Fields

The recent large X-ray survey in three LSST deep-drilling fields (XMM-SERVS) provides a substantial number of active galactic nucleus (AGN) candidates (≈ 10,200) to characterize representative AGN populations, including those with heavy obscuration (N_H > 1.5×10²⁴ cm⁻²), along with their host galaxies. In this work, we extract X-ray spectra and perform spectral analyses to derive AGN characteristics (column density, X-ray luminosity, etc.). Adopting physical torus models (e.g., Borus02) and a Bayesian analysis approach, we uncover 22 representative Compton-Thick (CT) AGN candidates as well as a large sample of heavily obscured AGNs. We also obtain the properties of the host galaxies (e.g., dust extinction, star formation rate) using spectral energy distribution (SED) fits, aiming to discuss the contribution of obscuration to the co-evolution of AGNs and host galaxies. Our selected heavily-obscured AGN samples tend to show hard X-ray spectral features and significant dust obscuration, but a similar SFR distribution as the less-obscured AGN population. We further constrain the intrinsic distribution of AGN obscuration, and find an increasing intrinsic CT fraction (f_CT) from low to high redshift.