High-resolution X-ray observations of the central region of M31 with the Rosat satellite

We report the results of a 48,000 s observation of the central ∼34' of M31 with the ROSAT HRI. We detect 86 X-ray sources with luminosities above ∼1.4×10 36 ergs s -1 (3.5×10 -4 counts s -1 ). Eighteen sources are identified with globular clusters and two with supernova remnants. A point source coincident with the optical and radio nucleus is also detected. The cumulative luminosity distribution for all sources within 5' (∼1 kpc) of the nucleus flattens below ∼2×10 37 ergs s -1 . An extrapolation of this distribution to fainter luminosities indicates that only ∼15%-26% of the diffuse X-ray emission in the bulge can be attributed to faint unresolved sources from this distribution