Chandra Observations of M31 and their Implications for its ISM
  We have been regularly observing the bulge and inner disk of M31 for nearly 1 year, using both the HRC-I and ACIS-I instruments on the Chandra X-Ray Observatory. We present results from our program that are of interest to the study of the ISM in M31. In particular, we find that the unresolved emission within 3' of the center of M31 has a distinctly softer spectrum than that of most of the resolved x-ray sources in the region. Preliminary spectral analysis of bright point sources in the bulge shows no evidence (within the poor statistics) for soft spectral components, but does reveal significant extra-galactic x-ray extinction (NH~1E21). We find no new x-ray counterparts to supernova remnants to date. 
F. Primini, M. Garcia, S. Murray, W. Forman, C. Jones, J. McClintock