Chandra Follow-up Observations of Swift-BAT-selected AGNs II

We present the combined Chandra and Swift-BAT spectral analysis of nine low-redshift (z ≤ 0.10), candidate heavily obscured active galactic nuclei (AGN) selected from the Swift-BAT 150 month catalog. We located soft (1-10 keV) X-ray counterparts to these BAT sources and joint fit their spectra with physically motivated models. The spectral analysis in the 1-150 keV energy band determined that all sources are obscured, with a line-of-sight column density N _H ≥ 10²² cm^-2 at a 90% confidence level. Four of these sources show significant obscuration with N _H ≥ 10²³ cm^-2 and two additional sources are candidate Compton-thick Active Galactic Nuclei (CT-AGNs) with N _H ≥ 10²⁴ cm^-2. These two sources, 2MASX J02051994-0233055 and IRAS 11058-1131, are the latest addition to the previous 3 CT-AGN candidates found using our strategy for soft X-ray follow-up of BAT sources. Here we present the results of our methodology so far, and analyze the effectiveness of applying different selection criteria to discover CT-AGN in the local Universe. Our selection criteria has an ~20% success rate of discovering heavily obscured AGN whose CT nature is confirmed by follow-up NuSTAR observations. This is much higher than the ~5% found in blind surveys.