Discovery of 20 UV Emitting SNRs in M31 with UVIT

Abstract

We present the first catalog of supernova remnants (SNRs) in M31 which exhibit diffuse ultraviolet (UV) emission. UV images of M31 were obtained by the Ultraviolet Imaging Telescope (UVIT) on the AstroSat satellite, and the list of SNRs was obtained from X-ray, optical and radio catalogues of SNRs in M31. We used the UVIT images to find SNRs with diffuse emission, omitting those too contaminated with stellar emission. 20 SNRs in M31 were detected with diffuse UV emission. Fluxes in the UVIT F148W, F169M, F172M, N219M and N279N filters are measured for these SNRs. The luminosities are compared to those computed from the spectra of seven known UV-emitting SNRs in the Milky Way, the LMC, and the SMC. We find similar spectral shapes between the known and the M31 UV-emitting SNRs. The spectral shapes and the diffuse nature of the emission are good evidence that the UV emissions are dominated by line emissions, like known SNRs, and the UV is associated with the SNRs. Models are applied to the 6 SNRs with X-ray spectra. The main difference is that the 2 X-ray/UV SNRs are Type Ia and the 4 X-ray/non-UV SNRs are core-collapse or unknown type. A comparison of M31 SNRs in different wavebands shows that most are detected optically, similar to the case for other nearby galaxies. 19 of the 20 UV-emitting SNRs are detected optically, expected because both UV and optical are from forbidden and recombination lines from shock-ionized gas.

arXiv comment17 pages, 7 figures

References in corpus (24)

• Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3
• An Analysis of the Shapes of Interstellar Extinction Curves. V. The IR-Through-UV Curve Morphology
• A revised catalogue of 294 Galactic supernova remnants
• The Panchromatic Hubble Andromeda Treasury X. Ultraviolet to Infrared Photometry of 117 Million Equidistant Stars
• In-orbit Calibrations of the Ultra-Violet Imaging Telescope
• Additional Calibration of the Ultra-Violet Imaging Telescope on board AstroSat
• The XMM-Newton serendipitous ultraviolet source survey catalogue
• Statistical Analysis of Supernova Remnants in the Large Magellanic Cloud
• The deep XMM-Newton Survey of M 31
• A Spectroscopic Survey of Massive Stars in M31 and M33
• A New Optical Survey of Supernova Remnant Candidates in M31
• Evolutionary Models for 43 Galactic Supernova Remnants with Distances and X-ray Spectra
• A Python Calculator for Supernova Remnant Evolution
• The supernova remnant population of the Small Magellanic Cloud
• Supernova remnants and candidates detected in the XMM-Newton M31 large survey
• The Red Supergiant Content of M31 and M33
• Energetics and Birth Rates of Supernova Remnants in the Large Magellanic Cloud
• 20 cm VLA Radio-Continuum Study of M31 - Images and Point Source Catalogues DR2: Extraction of a supernova remnant sample
• New Optically Identified Supernova Remnants in the Large Magellanic Cloud
• Emission Measures and Emission-measure-weighted Temperatures of Shocked ISM and Ejecta in Supernova Remnants
• The Ultraviolet Extinction Map and Dust Property at High Galactic Latitude
• Deep XMM-Newton observations of the northern disc of M31. I. Source catalogue
• Physical Properties of the Supernova Remnant Population in the Small Magellanic Cloud
• AstroSat/UVIT Cluster Photometry in the Northern Disk of M31