Exploring the X-ray emission properties of the supernova remnant G67.7+1.8 and its central X-ray sources

TL;DR

This study uses Chandra X-ray observations to analyze the supernova remnant G67.7+1.8, revealing thermal plasma emission, elemental overabundances, and potential compact remnants near the remnant's center.

Contribution

First detailed X-ray spectral and morphological analysis of G67.7+1.8, identifying elemental overabundances and candidate compact objects within the remnant.

Findings

X-ray morphology matches radio double-arc structure

Detection of overabundant magnesium, silicon, and sulphur

Identification of potential compact stellar remnants

Abstract

We have studied the supernova remnant G67.7+1.8 with the Chandra X-ray observatory. The remnant's X-ray morphology correlates well with the double-arc structure seen at radio wavelength. The X-ray spectra of the northern and southern rim of G67.7+1.8 exhibit emission line features of highly ionized metals, which suggests that most of the observed X-rays originate in a thermal plasma. We find magnesium, silicon, and sulphur are overabundant relative to the solar values. Gaussian emission lines at $\sim4$ keV and $\sim7$ keV are detected. The $\sim4$ keV line is consistent with K-emission lines from $^{44}$Ca and/or $^{44}$Sc whereas the $\sim7$ keV line feature may arise from unresolved Fe-K lines. Chandra's sub-arcsecond angular resolution allowed us to detect four faint point sources located within $\sim1.5$ arc-minutes of the geometrical remnant center. Among these objects, CXOU195424.75+312824.9 and CXOU195429.82+312834.1 do not have optical counterparts, leaving them as candidates for a possible compact stellar remnant.