Radio continuum observations of LMC SNR J0550-6823

Resumen

We report on new Australia Telescope Compact Array (ATCA) observations of the Large Magellanic Cloud (LMC) supernova remnant (SNR) J0550-6823 (DEM L328). This object is a typical horseshoe SNR with a diameter of 373″ × 282″ ± 4″ (90 × 68 ± 1 pc), making it one of the largest known SNRs in the Local Group. We estimate a relatively steep radio spectral index of α=−0.79 ± 0.27. However, its stronger than expected polarisation of 50% ± 10% is atypical for older and more evolved SNRs. We also note a strong correlation between O III and radio images, classifying this SNR as oxygen dominant.