An XMM-Newton Study of the Mixed-Morphology Supernova Remnant G346.6-0.2

TL;DR

This study uses XMM-Newton observations to analyze the X-ray properties of the mixed-morphology supernova remnant G346.6-0.2, revealing a recombining plasma and potential high-energy emission components.

Contribution

First detailed X-ray spectral analysis of G346.6-0.2 revealing recombining plasma and possible high-energy emission origins.

Findings

Recombining plasma with sub-solar Mg, Si, S abundances.

Possible additional power-law or thermal component.

Remnant likely from a core-collapse supernova.

Abstract

We present an X-ray imaging and spectroscopic study of the molecular cloud interacting mixed-morphology (MM) supernova remnant (SNR) G346.6-0.2 using XMM-Newton. The X-ray spectrum of the remnant is well described by a recombining plasma that most likely arises from adiabatic cooling, and has sub-solar abundances of Mg, Si, and S. Our fits also suggest the presence of either an additional power-law component with a photon index of $\sim$2, or an additional thermal component with a temperature of $\sim$2.0 keV. We investigate the possible origin of this component and suggest that it could arise from either the Galactic ridge X-ray emission, an unidentified pulsar wind nebula or X-ray synchrotron emission from high-energy particles accelerated at the shock. However, deeper, high resolution observations of this object are needed to shed light on the presence and origin of this feature. Based on its morphology, its Galactic latitude, the density of the surrounding environment and its association with a dense molecular cloud, G346.6-0.2 most likely arises from a massive progenitor that underwent core-collapse.