First Study of the Supernova Remnant Population in the Large Magellanic Cloud with eROSITA
Résumé
The study of the entire population of SNRs in a galaxy helps us to understand the underlying stellar populations, the environments, in which the SNRs are evolving, and the stellar feedback on the ISM. The all-sky survey carried out by the extended Roentgen Survey with an Imaging Telescope Array (eROSITA) on board Spektrum-Roentgen-Gamma (Spektr-RG, SRG) has provided us with spatially and spectrally resolved X-ray data of the entire Large Magellanic Cloud (LMC) and its immediate surroundings in the soft X-ray band down to 0.2 keV. We performed a multiwavelength analysis of previously known SNR candidates and newly detected SNRs and SNR candidates. We applied the Gaussian gradient magnitude (GGM) filter to the eROSITA images of the LMC to highlight the edges of the shocked gas in order to find new SNRs. We compared the X-ray images with those of their optical and radio counterparts to investigate the true nature of the extended emission. We used the Magellanic Cloud Emission Line Survey (MCELS) for the optical data. For the radio comparison, we used data from the Australian Square Kilometre Array Pathfinder (ASKAP) survey of the LMC. Using the VISTA survey of the Magellanic Clouds (VMC) we have investigated the possible progenitors of the new SNRs and SNR candidates in our sample. We present the most updated catalogue of SNRs in the LMC. The eROSITA data have allowed us to confirm two of the previous SNR candidates and discover 16 new extended sources. We confirm 3 of them as new SNRs, while we propose the remaining 13 as new X-ray SNR candidates. We also present the first analysis of the follow-up XMM-Newton observation of MCSNR J0456-6533 discovered with eROSITA. Among the new candidates, we propose J0614-7251 (4eRASSU J061438.1-725112) as the first X-ray SNR candidate in the outskirts of the LMC.