The 70-month Swift/BAT catalogue provides a sensitive view of the extragalactic X-ray sky at hard energies (>10 keV) containing about 800 Active Galactic Nuclei. We explore its content in heavily obscured, Compton-thick AGN by combining the BAT (14-195 keV) with the lower energy XRT (0.3-10 keV) data. We apply a Bayesian methodology using Markov chains to estimate the exact probability distribution of the column density for each source. We find 53 possible Compton-thick sources (with probability 3 to 100%) translating to a ~7% fraction of the AGN in our sample. We derive the first parametric luminosity function of Compton-thick AGN. The unabsorbed luminosity function can be represented by a double power-law with a break at L⋆2×1042ergss−1 in the 20-40 keV band.
@article{arxiv.1607.08069,
title = {Compton Thick AGN in the 70 Month Swift-BAT All-Sky Hard X-ray Survey: a Bayesian approach},
author = {A. Akylas and I. Georgantopoulos and P. Ranalli and E. Gkiokas and A. Corral and G. Lanzuisi},
journal= {arXiv preprint arXiv:1607.08069},
year = {2016}
}