XMM-Newton Studies of the Supernova Remnant G350.0$-$2.0

TL;DR

XMM-Newton observations of supernova remnant G350.0-2.0 reveal diffuse thermal X-ray emission from shocked interstellar material, with some bright blobs showing Fe overabundance, and identify a complex X-ray source with possible cataclysmic variable or pulsar nature.

Contribution

First detailed X-ray study of G350.0-2.0 revealing plasma properties and potential compact object counterparts, including analysis of the bright X-ray source's nature.

Findings

Diffuse thermal X-ray emission with solar abundances from shocked interstellar medium.

Bright blobs exhibit Fe overabundance, indicating localized enrichment.

X-ray source 1RXS J172653.4-382157 may be a cataclysmic variable or pulsar.

Abstract

We report the results of XMM-Newton observations of the Galactic mixed-morphology supernova remnant G350.0$-$2.0. Diffuse thermal X-ray emission fills the north-western part of the remnant surrounded by radio shell-like structures. We did not detect any X-ray counterpart of the latter structures, but found several bright blobs within the diffuse emission. The X-ray spectrum of the most part of the remnant can be described by a collisionally-ionized plasma model VAPEC with solar abundances and a temperature of $\approx 0.8$ keV. The solar abundances of plasma indicate that the X-ray emission comes from the shocked interstellar material. The overabundance of Fe was found in some of the bright blobs. We also analysed the brightest point-like X-ray source 1RXS J172653.4$-$382157 projected on the extended emission. Its spectrum is well described by the two-temperature optically thin thermal plasma model MEKAL typical for cataclysmic variable stars. The cataclysmic variable source nature is supported by the presence of a faint ($g\approx21$) optical source with non-stellar spectral energy distribution at the X-ray position of 1RXS J172653.4$-$382157. It was detected with the XMM-Newton optical/UV monitor in the $U$ filter and was also found in the archival H$\alpha$ and optical/near-infrared broadband sky survey images. On the other hand, the X-ray spectrum is also described by the power law plus thermal component model typical for a rotation powered pulsar. Therefore, the pulsar interpretation of the source cannot be excluded. For this source, we derived the upper limit for the pulsed fraction of 27 per cent.