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arXiv · 2202.10496

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

Ross Silver·Nuria Torres-Alba·Xiurui Zhao·Stefano Marchesi·Andrealuna Pizzetti·Marco Ajello·Giancarlo Cusumano·Valentina Parola·Alberto Segreto·Andrea Comastri
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Abstract

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 NH >= 10^22 cm^-2 at a 90% confidence level. Four of these sources show significant obscuration with NH >= 10^23 cm^-2 and two additional sources are candidate Compton-thick Active Galactic Nuclei (CT-AGNs) with NH >= 10^24 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. In 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 a ~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.

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Ross Silver, Nuria Torres-Alba, Xiurui Zhao, Stefano Marchesi, Andrealuna Pizzetti, Marco Ajello, Giancarlo Cusumano, Valentina Parola, Alberto Segreto, Andrea Comastri. 2022-02-21. Chandra Follow-up Observations of Swift-BAT-selected AGNs II. https://doi.org/10.3847/1538-4357/ac67a2

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