Suzaku Observations of Ejecta-Dominated Galactic Supernova Remnant G346.6-0.2

TL;DR

This paper reports Suzaku X-ray observations of the supernova remnant G346.6-0.2, revealing ejecta-dominated emission, detailed plasma properties, and evidence supporting a Type Ia supernova origin.

Contribution

First detection of K-shell emission lines of Mg, Si, S, Ca, and Fe in G346.6-0.2, and comprehensive plasma modeling indicating a Type Ia supernova origin.

Findings

Ejecta-dominated X-ray emission confirmed by emission lines.

High-density medium with N_H ~ 2.1×10^22 cm^-2.

Remnant likely from a Type Ia supernova.

Abstract

We present here the results of the X-ray analysis of Galactic supernova remnant G346.6-0.2 observed with {\it Suzaku}. K-shell emission lines of Mg, Si, S, Ca and Fe are detected clearly for the first time. Strong emission lines of Si and S imply that X-ray emission nature of G346.6-0.2 is ejecta-dominated. The ejecta-dominated emission is well fitted with a combined model consisting of thermal plasma in non-equilibrium ionization and a non-thermal component, which can be regarded as synchrotron emission with a photon index of $\Gamma$ $\sim 0.6$. Absorbing column density of $N_{\rm H}\sim2.1\times10^{22}$ ${\rm cm^{-2}}$ is obtained from the best-fitting implying a high-density medium, high electron temperature of $kT_{\rm e}\sim1.2$ keV, and ionization timescale of $n_{\rm e}t\sim2.9\times10^{11}$ ${\rm cm^{-3}s}$ indicating that this remnant may be far from full ionization equilibrium. The relative abundances from the ejecta show that the remnant originates from a Type Ia supernova explosion.