XMM-Newton observations of the non-thermal supernova remnant HESS J1731-347 (G353.6-0.7)

TL;DR

This study presents comprehensive XMM-Newton X-ray observations of the supernova remnant HESS J1731-347, revealing a non-thermal shell with spatially variable absorption, and discusses its interaction with surrounding molecular clouds and implications for shock velocities.

Contribution

First complete X-ray coverage of the remnant shell enabling detailed spatial spectral analysis and correlation with radio and TeV data, confirming non-thermal emission and variable absorption features.

Findings

Confirmed non-thermal power-law X-ray spectrum with uniform spectral index

Variable X-ray absorption correlates with CO emission, indicating foreground material

Suppressed X-ray emission near the Galactic plane suggests lower shock velocities due to molecular cloud interaction

Abstract

We report on the analysis of XMM-Newton observations of the non-thermal shell-type supernova remnant HESS J1731-347 (G353.6-0.7). For the first time the complete remnant shell has been covered in X-rays, which allowed direct comparison with radio and TeV observations. We carried out a spatially resolved spectral analysis of XMM-Newton data and confirmed the previously reported non-thermal power-law X-ray spectrum of the source with negligible variations of spectral index across the shell. On the other hand, the X-ray absorption column is strongly variable and correlates with the CO emission thus confirming that the absorbing material must be in the foreground and reinforcing the previously suggested lower limit on distance. Finally, we find that the X-ray emission of the remnant is suppressed towards the Galactic plane, which points to lower shock velocities in this region, likely due to the interaction of the shock with the nearby molecular cloud.