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

Max-Planck Institut für Extraterrestrische Physik, Giessenbachstrasse 1, 85741 Garching bei München, Germany e-mail: dhui@mpe.mpg.de

Received: 12 August 2008
Accepted: 4 December 2008

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 overabundant relative to the solar values. Gaussian emission lines at ~4 keV and ~7 keV are detected. The ~4 keV line is consistent with K-emission lines from ⁴⁴Ca and/or ⁴⁴Sc whereas the ~7 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 ~1.5 arcmin 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.