New Identification of the Mixed-Morphology Supernova Remnant G298.6-0.0 with Possible Gamma-ray Association

TL;DR

This study analyzes the mixed-morphology supernova remnant G298.6-0.0 using Suzaku X-ray data, revealing its plasma characteristics and potential association with a gamma-ray source, contributing to understanding SNR evolution and gamma-ray origins.

Contribution

The paper provides the first detailed X-ray analysis of G298.6-0.0 and suggests a likely gamma-ray counterpart, highlighting the evolution of flux ratios in mixed-morphology SNRs.

Findings

G298.6-0.0 is a mixed-morphology SNR with a plasma temperature of 0.78 keV.

The plasma mass indicates an interstellar medium origin.

The gamma-ray source 3FGL J1214.0-6236 is likely associated with G298.6-0.0.

Abstract

We present an X-ray analysis on the Galactic supernova remnant (SNR) G298.6-0.0 with Suzaku. The X-ray image shows a center-filled structure inside the radio shell, implying this SNR is categorized as a mixed-morphology (MM) SNR. The spectrum is well reproduced by a single temperature plasma model in ionization equilibrium, with a temperature of 0.78 (0.70-0.87) keV. The total plasma mass of 30 solar mass indicates that the plasma has interstellar medium origin. The association with a GeV gamma-ray source 3FGL J1214.0-6236 on the shell of the SNR is discussed, in comparison with other MM SNRs with GeV gamma-ray associations. It is found that the flux ratio between absorption-corrected thermal X-rays and GeV gamma-rays decreases as the MM SNRs evolve to larger physical sizes. The absorption-corrected X-ray flux of G298.6-0.0 and the GeV gamma-ray flux of 3FGL J1214.0-6236 closely follow this trend, implying that 3FGL J1214.0-6236 is likely to be the GeV counterpart of G298.6-0.0.