An X-ray characterization of the central region of the SNR G332.5-5.6

TL;DR

This paper presents an X-ray and infrared analysis of supernova remnant G332.5-5.6, revealing its soft X-ray emission, correlation with radio features, and evidence of expansion into a medium with an abrupt density change.

Contribution

It provides the first detailed spectral analysis of G332.5-5.6's X-ray emission, identifying its thermal plasma nature and interaction with a dense infrared-emitting region.

Findings

X-ray emission is predominantly soft and peaks around 0.5 keV.

X-ray and radio emissions are spatially correlated, especially on the west side.

The remnant is expanding into a medium with an abrupt density change.

Abstract

We present an X-ray analysis of the central region of supernova remnant (SNR) G332.5-5.6 through an exhaustive analysis of XMM-Netwon observations with complementary infrared observations. We characterize and discuss the origin of the observed X-ray morphology, which presents a peculiar plane edge over the west side of the central region. The morphology and spectral properties of the X-ray supernova remnant were studied using a single full frame XMM-Newton observation in the 0.3 to 10.0 keV energy band. Archival infrared WISE observations at 8, 12 and 24 \mu m were also used to investigate the properties of the source and its surroundings at different wavelengths. The results show that the extended X-ray emission is predominantly soft (0.3-1.2 keV) and peaks around 0.5 keV, which shows that it is an extremely soft SNR. X-ray emission correlates very well with central regions of bright radio emission. On the west side the radio/X-ray emission displays a plane-like feature with a terminal wall where strong infrared emission is detected. Our spatially resolved X-ray spectral analysis confirms that the emission is dominated by weak atomic emission lines of N, O, Ne, and Fe, all of them undetected in previous X-ray studies. These characteristics suggest that the X-ray emission is originated in an optically thin thermal plasma, whose radiation is well fitted by a non-equilibrium ionization collisional plasma (VNEI) X-ray emission model. Our study favors a scenario where G332.5-5.6 is expanding in a medium with an abrupt density change (the wall), likely a dense infrared emitting region of dust on the western side of the source.