X-ray emission from HESS J1731-347/SNR G353.6-0.7 and Central Compact Source XMMS J173203-344518

TL;DR

This study investigates the X-ray and gamma-ray emissions from SNR G353.6-0.7 and HESS J1731-347, revealing non-thermal X-ray spectra, a potential magnetar candidate, and evidence of SNR-cloud interaction as the gamma-ray source.

Contribution

The paper provides new X-ray observations of the SNR and TeV source, identifies a possible magnetar-like compact object, and suggests SNR-cloud interaction as the origin of gamma-ray emission.

Findings

Extended hard X-ray emission coincides with the TeV source and SNR shell.

Detection of a compact X-ray source with magnetar-like spectrum.

Evidence of SNR interaction with nearby CO clouds at 3.2 kpc.

Abstract

We present new results of the HESS J1731-347/SNR G353.6-0.7 system from XMM-NEWTOM and Suzaku X-ray observations, and Delinha CO observations. We discover extended hard X-rays coincident with the bright, extended TeV source HESS J1731-347 and the shell of the radio SNR. We find that spatially-resolved X-ray spectra can generally be characterized by an absorbed power-law model, with photon-index of ~ 2, typical of non-thermal emission. A bright X-ray compact source, XMMS J173203-344518, is also detected near the center of the SNR. We find no evidence of a radio counterpart or an extended X-ray morphology for this source, making it unlikely to be a pulsar wind nebular (PWN). The spectrum of the source can be well fitted by an absorbed blackbody with a temperature of ~ 0.5 keV plus a power-law tail with a photon-index of ~ 5, reminiscent of the X-ray emission of a magnetar. CO observations toward the inner part of the HESS source reveal a bright cloud component at -20+/-4 km s^{-1}, which is likely located at the same distance of ~ 3.2 kpc as the SNR. Based on the probable association between the X-ray and $\gamma$-ray emissions and likely association between the CO cloud and the SNR, we argue that the extended TeV emission originates from the interaction between the SNR shock and the adjacent CO clouds rather than from a PWN.