A deep XMM-Newton survey of M 31

TL;DR

This paper reports on the initial results of a comprehensive deep X-ray survey of M 31 using XMM-Newton, aiming to catalog and classify various X-ray sources in the galaxy.

Contribution

It presents the first data and methodology for a detailed X-ray inventory of M 31, including source detection and classification strategies.

Findings

Detected about 1000 sources in initial observations

Full survey expected to find around 2000 sources

Developed classification methods using multi-wavelength data

Abstract

The deep homogeneous survey of the large Local-Group spiral galaxy M 31 is a milestone project for X-ray astronomy, as it allows a detailed X-ray inventory of an archetypal low-star-formation-rate galaxy like our own. We present first results of the deep XMM-Newton survey, which covers the entire D 25 ellipse. Information from different X-ray energy bands are combined in an X-ray colour image of M 31. In the first 15 observations we found about 1000 sources, the full survey will yield about 2000 X-ray sources. Sources will be classified using hardness ratios, extent, high quality spectra and time variability. In addition the sources will be correlated with catalogues in optical, infra-red and radio wavelengths. Our goal is to study M 31 X-ray binaries and globular cluster sources, supersoft sources, supernova remnants and the hot interstellar medium and separate them from foreground stars and background objects.