Extended X-ray Emission in Compton Thick AGN with Deep Chandra Observations

TL;DR

This study analyzes high-resolution Chandra observations of five Compton thick AGNs, revealing extended hard X-ray emission on kiloparsec scales and its correlation with obscuration and galactic structures, advancing understanding of this AGN population.

Contribution

First detailed spatial analysis of extended hard X-ray emission in a sample of Compton thick AGNs, linking emission properties to obscuration and galaxy features.

Findings

Extended hard X-ray emission observed up to ~kpc scales.

Correlation between excess emission and nuclear obscuration.

Soft X-ray emission extends farther than hard X-rays along ionization cones.

Abstract

We present the spatial analysis of five Compton thick (CT) active galactic nuclei (AGNs), including MKN 573, NGC 1386, NGC 3393, NGC 5643, and NGC 7212, for which high resolution Chandra observations are available. For each source, we find hard X-ray emission (>3 keV) extending to ~kpc scales along the ionization cone, and for some sources, in the cross-cone region. This collection represents the first, high-signal sample of CT AGN with extended hard X-ray emission for which we can begin to build a more complete picture of this new population of AGN. We investigate the energy dependence of the extended X-ray emission, including possible dependencies on host galaxy and AGN properties, and find a correlation between the excess emission and obscuration, suggesting a connection between the nuclear obscuring material and the galactic molecular clouds. Furthermore, we find that the soft X-ray emission extends farther than the hard X-rays along the ionization cone, which may be explained by a galactocentric radial dependence on the density of molecular clouds due to the orientation of the ionization cone with respect to the galactic disk. These results are consistent with other CT AGN with observed extended hard X-ray emission (e.g., ESO 428-G014 and the Ma et al. 2020 CT AGN sample), further demonstrating the ubiquity of extended hard X-ray emission in CT AGN.