G332.5-5.6, a new Galactic supernova remnant

Abstract

We present radio observations of the source G332.5-5.6, a candidate supernova remnant (SNR). Observations have been performed with the Australia Telescope Compact Array (ATCA) at two frequencies, at 1.4 and 2.4 GHz. Our results confirm that G332.5-5.6 is an SNR, with a spectral index equal to -0.7 +/- 0.2 for the whole source and an average fractional polarization of ~35% at 2.4 GHz. The central component is coincident with extended X-ray emission and the distance to the SNR is estimated to be ~3.4 kpc. Based on its radio and X-ray morphology, this SNR should be classified as a composite, and we suggest that it belongs to a trident-shaped subclass like G291.0-0.1.

Accepted for publication in Monthly Notices of the Royal Astronomical Society