SNR and HII regions in M83 observed with MUSE

Our revised catalog of SNR candidates in M83 has 366 objects, 81 of which are reported here for the first time. Of these, 229 lie within the MUSE observation region, 160 of which have spectra with [SII]:H{alpha} ratios exceeding 0.4, the value generally accepted as confirmation that an emission nebula is shock-heated.

Combined with 51 SNR candidates outside the MUSE region with high [SII]:H{alpha} ratios, there are 211 spectroscopically confirmed SNRs in M83, the largest number of confirmed SNRs in any external galaxy. MUSE's combination of relatively high spectral resolution and broad wavelength coverage has allowed us to explore two other properties of SNRs that could serve as the basis of future SNR searches. Specifically, most of the objects identified as SNRs on the basis of [SII]:H{alpha} ratios exhibit more velocity broadening and lower ratios of [SIII]:[SII] emission than HII regions.