Compton-Thick AGN in the NuSTAR era VII. A joint NuSTAR, Chandra and XMM-Newton analysis of two nearby, heavily obscured sources

TL;DR

This study analyzes two nearby heavily obscured Seyfert galaxies using joint X-ray data from Chandra, XMM-Newton, and NuSTAR, revealing their complex obscuration properties and the patchy nature of their circumnuclear material.

Contribution

It provides the first combined NuSTAR, Chandra, and XMM-Newton analysis of these sources, offering detailed estimates of their column densities and obscuring torus covering factors.

Findings

NGC 3081 has a Compton-thin line-of-sight but a Compton-thick average column density.

ESO 565-G019 is confirmed as Compton-thick both in line-of-sight and average densities.

The obscuring torus covering factors are constrained to 0.63-0.82 for NGC 3081 and 0.39-0.65 for ESO 565-G019.

Abstract

We present the joint Chandra, XMM-Newton and NuSTAR analysis of two nearby Seyfert galaxies, NGC 3081 and ESO 565-G019. These are the only two having Chandra data in a larger sample of ten low redshift ($z \le 0.05$), candidates Compton-thick Active Galactic Nuclei (AGN) selected in the 15-150 keV band with Swift-BAT that were still lacking NuSTAR data. Our spectral analysis, performed using physically-motivated models, provides an estimate of both the line-of-sight (l.o.s.) and average (N$_{H,S}$) column densities of the two torii. NGC 3081 has a Compton-thin l.o.s. column density N$_{H,z}$=[0.58-0.62] $\times 10^{24}$cm$^{-2}$, but the N$_{H,S}$, beyond the Compton-thick threshold (N$_{H,S}$=[1.41-1.78] $\times 10^{24}$cm$^{-2}$), suggests a "patchy" scenario for the distribution of the circumnuclear matter. ESO 565-G019 has both Compton-thick l.o.s. and N$_{H,S}$ column densities (N$_{H,z}>$2.31 $\times 10^{24}$cm$^{-2}$ and N$_{H,S} >$2.57 $\times 10^{24}$cm$^{-2}$, respectively). The use of physically-motivated models, coupled with the broad energy range covered by the data (0.6-70 keV and 0.6-40 keV, for NGC 3081 and ESO 565-G019, respectively) allows us to constrain the covering factor of the obscuring material, which is C$_{TOR}$=[0.63-0.82] for NGC 3081, and C$_{TOR}$=[0.39-0.65] for ESO 565-G019.