A High‐Resolution Study of Nonthermal Radio and X‐Ray Emission from Supernova Remnant G347.3−0.5

Abstract

G347.3-0.5 is one of three shell-type supernova remnants (SNRs) in the Galaxy whose X-ray spectrum is dominated by nonthermal emission. This puts G347.3-0.5 in the small but growing class of SNRs for which the X-ray emission reveals directly the presence of extremely energetic electrons accelerated by the SNR shock. We have obtained new high-resolution X-ray and radio data on G347.3-0.5 using the Chandra X-Ray Observatory and the Australia Telescope Compact Array (ATCA), respectively. The bright northwestern peak of the SNR seen in ROSAT and ASCA images is resolved with Chandra into bright filaments and fainter diffuse emission. These features show good correspondence with the radio morphological structure, providing strong evidence that the same population of electrons is responsible for the synchrotron emission in both bands in this part of the remnant. Spectral index information from both observations is presented. We found significant difference in photon index value between bright and faint regions of the SNR shell. Spectral properties of these regions support the notion that efficient particle acceleration is occurring in the bright SNR filaments. We report the detection of linear radio polarization toward the SNR, which is most ordered at the northwestern shell where particle acceleration is presumably occurring. Using our new Chandra and ATCA data, we model the broadband emission from G347.3-0.5 with the synchrotron and inverse Compton mechanisms and discuss the conditions under which this is a plausible scenario.