M. Sasaki1, W. Pietsch2, F. Haberl2, D. Hatzidimitriou3, H. Stiele4, B. Williams5, A. Kong6 and U. Kolb7
1 Institut für Astronomie und Astrophysik, Universität Tübingen, Sand 1, 72076 Tübingen, Germany
2 Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße, 85748 Garching, Germany
3 Department of Astrophysics, Astronomy and Mechanics, Faculty of Physics, University of Athens, Panepistimiopolis, 15784 Zografos, Athens, Greece
4 INAF – Osservatorio Astronomico di Brera, via E. Bianchi 46, 23807 Merate (LC), Italy
5 Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195, USA
6 Institute of Astronomy and Department of Physics, National Tsing Hua University, 30013 Hsinchu, Taiwan
7 Dept of Physical Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK
Received: 13 February 2012
Accepted: 20 June 2012
Context. We present the analysis of supernova remnants (SNRs) and candidates in M 31 identified in the XMM-Newton large programme survey of M 31. Supernova remnants are among the brightest X-ray sources in a galaxy. They are good indicators of the recent star-formation activities of galaxies and the interstellar environment in which they evolve.
Aims. By combining the X-ray data of sources in M 31 with optical data as well as optical and radio catalogues, we aim to compile a complete, revised list of SNRs emitting X-rays in M 31 detected with XMM-Newton, study their luminosity and spatial distributions, and understand the X-ray spectra of the brightest SNRs.
Methods. We analysed the X-ray spectra of the 12 brightest SNRs and candidates that have been observed with XMM-Newton. Our study of the four brightest sources allowed us to perform a more detailed spectral analysis and compare different models to describe their spectrum. For all M 31 large programme sources, we searched for their optical counterparts in the Hα, [S ii], and [O iii] images of the Local Group Galaxy Survey.
Results. We confirm 21 X-ray sources as counterparts to known SNRs. In addition, we identify 5 new X-ray sources as X-ray and optically emitting SNRs. Seventeen sources are no longer considered as SNR candidates. We thus create a list of 26 X-ray SNRs and 20 X-ray SNR candidates in M 31 based on their X-ray, optical, and radio emission, which is the most recent complete list of X-ray SNRs in M 31. The brightest SNRs have X-ray luminosities of up to 8 × 1036 erg s-1 in the 0.35–2.0 keV band.
Key words: ISM: supernova remnants / galaxies: ISM / galaxies: individual: M 31 / X-rays: galaxies / X-rays: ISM
Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA.
Appendices are available in electronic form at http://www.aanda.org
© ESO, 2012