Supernova remnants and candidates detected in the XMM-Newton M31 large survey

TL;DR

This paper presents a comprehensive analysis of supernova remnants in M31 using XMM-Newton data, confirming known SNRs, identifying new ones, and providing detailed spectral and spatial information to enhance understanding of their properties.

Contribution

The study provides the most recent complete list of X-ray SNRs in M31, combining multi-wavelength data and detailed spectral analysis to improve identification and characterization.

Findings

Confirmed 21 X-ray SNR counterparts.

Identified 5 new X-ray and optical SNRs.

Created a list of 26 X-ray SNRs and 20 candidates.

Abstract

We present the analysis of supernova remnants (SNRs) and candidates in M31 identified in the XMM-Newton large programme survey of M31. SNRs are among the bright X-ray sources in a galaxy. They are good indicators of recent star formation activities of a galaxy and of the interstellar environment in which they evolve. By combining the X-ray data of sources in M31 with optical data as well as with optical and radio catalogues, we aim to compile a complete, revised list of SNRs emitting X-rays in M31 detected with XMM-Newton, study their luminosity and spatial distribution, and understand the X-ray spectrum of the brightest SNRs. We analysed the X-ray spectra of the twelve brightest SNRs and candidates using XMM-Newton data. The four brightest sources allowed us to perform a more detailed spectral analysis and the comparison of different models to describe their spectrum. For all M31 large programme sources we searched for optical counterparts on the Ha, [Sii], and [Oiii] images of the Local Group Galaxy Survey. We confirm 21 X-ray sources as counterparts of known SNRs. In addition, we identify five new X-ray sources as X-ray and optically emitting SNRs. Seventeen sources are no longer considered as SNR candidates. We have thus created a list of 26 X-ray SNRs and 20 candidates in M31 based on their X-ray, optical, and radio emission, which is the most recent complete list of X-ray SNRs in M31. The brightest SNRs have X-ray luminosities of up to 8 x 10^36 erg/s in the 0.35 - 2.0 keV band.