Multifrequency study of SNR J0533-7202, a new supernova remnant in the LMC

TL;DR

This study provides a detailed radio analysis of the newly discovered SNR J0533-7202 in the LMC, revealing its morphology, spectral properties, polarization, and potential supernova origin, with implications for understanding supernova remnants in the LMC.

Contribution

First detailed radio study of SNR J0533-7202, including morphology, spectral index, polarization, and rotation measure, suggesting a thermonuclear supernova origin.

Findings

Horseshoe morphology with size 37x28 pc.

Radio spectral index of -0.47 indicating synchrotron emission.

Polarization peak of 36% at 6 cm.

Abstract

We present a detailed study of Australia Telescope Compact Array (ATCA) observations of a newly discovered Large Magellanic Cloud (LMC) supernova remnant (SNR), SNR J0533-7202. This object follows a horseshoe morphology, with a size 37 pc x 28 pc (1-pc uncertainty in each direction). It exhibits a radio spectrum with the intrinsic synchrotron spectral index of alpha= -0.47+-0.06 between 73 and 6 cm. We report detections of regions showing moderately high fractional polarisation at 6 cm, with a peak value of 36+-6% and a mean fractional polarisation of 12+-7%. We also estimate an average rotation measure across the remnant of -591 rad m^-2. The current lack of deep X-ray observation precludes any conclusion about high-energy emission from the remnant. The association with an old stellar population favours a thermonuclear supernova origin of the remnant.