Supernova Remnant Candidates Discovered by the SARAO MeerKAT Galactic Plane Survey

Abstract

Context. Sensitive radio continuum data could remove the difference between the number of known supernova remnants (SNRs) in the Galaxy compared to that expected, but due to confusion in the Galactic plane, faint SNRs can be challenging to distinguish from brighter HII regions and filamentary radio emission. Aims. We wish to exploit new SARAO MeerKAT 1.3 GHz Galactic Plane Survey (SMGPS) radio continuum data, which covers $251°\le l\le 358°$ and $2°\le l\le 61°$ at $|b|\le 1.5°$, to search for SNR candidates in the Milky Way disk. Methods. We also use MIR data from the Spitzer GLIMPSE, Spitzer MIPSGAL, and WISE surveys to help identify SNR candidates. The identified SNR candidate are sources of extended radio continuum emission that lack MIR counterparts, are not known as HII regions in the WISE Catalog of Galactic HII Regions, and are not known previously as SNRs Results. We locate 237 new Galactic SNR candidates in the SMGPS data. We also identify and confirm the expected radio morphology for 201 objects listed in the literature as being SNRs and 130 previously-identified SNR candidates. The known and candidate SNRs have similar spatial distributions and angular sizes. Conclusions. The SMGPS data allowed us to identify a large population of SNR candidates that can be confirmed as true SNRs using radio polarization measurements or by deriving radio spectral indices. If the 237 candidates are confirmed as true SNRs, it would approximately double the number of known Galactic SNRs in the survey area, alleviating much of the difference between the known and expected populations.

Accepted by A&A. Images and FITS files of each source can be found here: https://doi.org/10.48479/0n8c-5q84

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Cited by in corpus (9)

• A Catalog of Galactic Supernova Remnants and Supernova Remnant Candidates from the EMU/POSSUM Radio Sky Surveys. I
• The SARAO MeerKAT Galactic Plane Survey extended source catalogue
• GaLactic and Extragalactic All-sky Murchison Widefield Array survey eXtended (GLEAM-X) III: Galactic Plane
• The infrared counterpart and proper motion of magnetar SGR0501+4516
• MeerKAT discovery of 164 compact radio rings toward the Galactic Plane
• Radio detection of supernova remnant G310.7-5.4 with $\gamma$-ray counterpart: Abeona SNR
• Heavy interstellar scattering toward the near end of the Galactic bar
• A global view on star formation: The GLOSTAR Galactic plane survey XII. Effelsberg's continuum view and data release
• A newly born spider system at the core of a radio shell: Evidence for a low-energy supernova