# X-ray spectral properties of seven heavily obscured Seyfert 2 galaxies

## TL;DR

This study combines Chandra and Swift-BAT data to analyze seven nearby Seyfert 2 galaxies, revealing significant obscuration and identifying potential Compton thick AGN, thus aiding understanding of obscuration in active galactic nuclei.

## Contribution

First combined spectral analysis of these galaxies over 0.3-150 keV, confirming high obscuration and testing a new spectral curvature method for identifying Compton thick AGN.

## Key findings

- All galaxies are significantly obscured with NH>=1E23 cm^(-2).
- One to three sources are candidate Compton thick AGN.
- Spectral curvature method agrees well with spectral analysis results.

## Abstract

We present the combined Chandra and Swift-BAT spectral analysis of seven Seyfert 2 galaxies selected from the Swift-BAT 100-month catalog. We selected nearby (z<=0.03) sources lacking of a ROSAT counterpart and never previously observed with Chandra in the 0.3-10 keV energy range, and targeted these objects with 10 ks Chandra ACIS-S observations. The X-ray spectral fitting over the 0.3-150 keV energy range allows us to determine that all the objects are significantly obscured, having NH>=1E23 cm^(-2) at a >99% confidence level. Moreover, one to three sources are candidate Compton thick Active Galactic Nuclei (CT-AGN), i.e., have NH>=1E24 cm^(-2). We also test the recent "spectral curvature" method developed by Koss et al. (2016) to find candidate CT-AGN, finding a good agreement between our results and their predictions. Since the selection criteria we adopted have been effective in detecting highly obscured AGN, further observations of these and other Seyfert 2 galaxies selected from the Swift-BAT 100-month catalog will allow us to create a statistically significant sample of highly obscured AGN, therefore better understanding the physics of the obscuration processes.