Astronomers have identified 20 ultraviolet-emitting supernova remnants in the Andromeda galaxy

Using the AstroSat satellite, astronomers from the University of Calgary, Canada, have located 20 supernova remnants (SNRs) in the Andromeda galaxy, which show diffuse ultraviolet emission. The findings are presented in a research paper published January 25 in the arXiv Preprint server, which can help us understand the origin and characteristics of UV emission in SNRs.

SNRs are diffuse, elongating structures generated by a Supernova explosion. They contain ejected matter expanding from the explosion and other interstellar material that has been swept away by the shock wave from the exploding star.

Studies of supernova remnants are important to Astronomy scientistsbecause it plays a major role in the evolution of galaxies, and the scattering of galaxies heavy items Made in a supernova explosion and provide the energy needed to heat the interstellar medium. SNRs are also thought to be responsible for accelerating galactic cosmic rays.

Although many extragalactic SNRs have been discovered so far, those that display ultraviolet emissions are hard to find, mainly due to the strong interstellar extinction of our galaxy in the ultraviolet. What is noteworthy, despite recent advances in UV-based SNR research, is that there is still no catalog of extragalactic UV-emitting SNRs.

That’s why a team of astronomers led by Dennis Leahy decided to conduct a search for ultraviolet-emitting SNRs in the nearby galaxy Andromeda (also known as Messier 31, or M31), with the goal of creating the first catalog of such objects in the last galaxy. For this purpose they used the AstroSat Ultraviolet Imaging Telescope (UVIT).

Ultraviolet images of M31 were obtained by the Ultraviolet Imaging Telescope on the AstroSat satellite, and a list of SNRs was obtained from the X-ray, optical and radio catalogs of SNRs in M31. We used UVIT images to find SNRs with diffuse emission, deleting those that are very polluted. by stellar emissions,” the researchers wrote in the paper.

The team initially selected 177 SNRs in order to investigate whether or not they display diffuse UV emissions. From the full sample, 20 of the supernova remnants were shown to be ultraviolet emitters. Selected sources display diffuse emission not associated with stars, although the strength of diffuse emission varies.

Astronomers compared the band luminosity of these 20 SNRs with the band luminosities of seven previously known ultraviolet-emitting SNRs in the Milky Way, the Large Magellanic Cloud (LMC) and Small Magellanic Clouds (SMC). As a result, they found similar spectral shapes between known SNRs and SNRs in the Andromeda galaxy. The results indicate that the emission of ultraviolet radiation from Supernova remnant reported in the paper that line emission is dominated and that this emission is associated with SNRs.

The study authors propose spectral observations to confirm the linear nature of the UV emissions from the newly identified SNRs. However, they point out that it would be difficult to perform spectral analysis of the normally crowded regions in the Andromeda galaxy where these SNRs are located.

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