ROSAT PSPC survey of M 31

Within the =~ 6.3deg^2^ field of view we detected 396 individual X-ray sources with (0.1keV-2.4keV) fluxes ranging from =~ 5x10^-15^erg/cm^2^/s^ to =~ 4x10^-12^erg/cm^2^/s. Of these 396 sources, 43 have be en tentatively identified with foreground stars, 29 with globular clusters, 17 with supernova remnants, 3 with other galaxies (including M 32), and 3 with radio sources.

A detailed analysis of the integral flux distribution of the sources shows that approximately one fifth are likely to be background objects. By comparison with the results of the Einstein M 31 survey, we find 327 newly detected sources, 15 moderately variable sources, 3 bright and 6 faint possible transient sources. For those sources in M 31, the observed luminosities range from =~ 3x10^35^erg/s to =~ 2x10^38^erg/s (at 690kpc).