Probing the Nature of a Very Luminous Globular Cluster X-Ray Source in M31
Abstract
We present results of a very bright M31 globular cluster (GC) X-ray source Bo375 from our Chandra, XMM-Newton, and Suzaku observations. Bo375 is one of the most luminous GC X-ray sources in M31 (Andromeda Galaxy), and has a luminosity consistently above 1038 erg/s, which is much more luminous than typical GCs found in our Milky Way galaxy. There are several possible explanations for such a high luminosity: 1) the source might contain multiple components; 2) the source radiation might be beamed; 3) the source might be an accreting black hole, and 4) the source might be a neutron star in which the mass transfer proceeds on the thermal time scale of the donor star. To investigate why Bo375 has such a high luminosity, we study the light curves, X-ray spectra, and timing properties of the source from the data taken by Chandra, XMM-Newton, and Suzaku in detail. Previous observations showed that Bo375 has short-term and long-term variability. The Chandra HRC-I data also shows that the source is consistent with a single point source. In this presentation, we will further show the new results from XMM-Newton and Suzaku, which might reveal the nature of Bo375, and of other luminous GCs in nearby galaxies.
- Publication:
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AAS/High Energy Astrophysics Division #10
- Pub Date:
- March 2008
- Bibcode:
- 2008HEAD...10.1030Y