In an analysis of XMM-Newton archival observations of the bright Local Group spiral galaxy M~31 we study the population of X-ray sources ( X-ray binaries , supernova remnants ) down to a 0.2–4.5 keV luminosity of 4.4 \times 10 ^ { 34 } erg s ^ { -1 } .
EPIC hardness ratios and optical and radio information are used to distinguish between different source classes .
The survey detects in an area of 1.24 square degree 856 sources .
We correlate our sources with earlier M~31 X-ray catalogues and use information from optical , infra-red and radio wavelengths .
As M~31 sources we detect 21 supernova remnants ( SNR ) and 23 SNR candidates , 18 supersoft source ( SSS ) candidates , 7 X-ray binaries ( XRBs ) and 9 XRB candidates , as well as 27 globular cluster sources ( GlC ) and 10 GlC candidates , which most likely are low mass XRBs within the GlC .
Comparison to earlier X-ray surveys reveal transients not detected with XMM-Newton , which add to the number of M~31 XRBs .
There are 567 sources classified as hard , which may either be XRBs or Crab-like SNRs in M~31 or background AGN .
The number of 44 SNRs and candidates more than doubles the X-ray detected SNRs .
22 sources are new SNR candidates in M~31 based on X-ray selection criteria .
Another SNR candidate may be the first plerion detected outside the Galaxy and the Magellanic Clouds .
On the other hand , six sources are foreground stars and 90 foreground star candidates , one is a BL Lac type active galactic nucleus ( AGN ) and 36 are AGN candidates , one source coincides with the Local Group galaxy M 32 , one with a background galaxy cluster ( GCl ) and another is a GCl candidate , all sources not connected to M~31 .