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M 31 XMM-Newton Spectral Survey X-Ray Point Source Catalog

Published by High Energy Astrophysics Science Archive Research Center | National Aeronautics and Space Administration | Metadata Last Checked: October 22, 2025 | Last Modified: 2025-09-10
This table contains the results of a complete spectral survey of the X-ray point sources detected in five XMM-Newton observations along the major axis of M 31 but avoiding the central bulge, aimed at establishing the population characteristics of X-ray sources in this galaxy. One observation of each disc field of M 31 was taken using the EPIC pn and MOS cameras on XMM-Newton in January and June 2002. The authors obtained background-subtracted spectra and lightcurves for each of the 335 X-ray point sources detected across the five observations from 2002. They also correlate their source list with those of earlier X-ray surveys and radio, optical and infra-red catalogs. Sources with more than 50 source counts are individually spectrally fit in order to create the most accurate luminosity functions of M 31 to date. Based on the spectral fitting of these sources with a power law model, the authors observe a broad range of best-fit photon index. From this distribution of best-fit index, they identify 16 strong high mass X-ray binary system candidates in M 31. They show the first cumulative luminosity functions created using the best-fit spectral model to each source with more than 50 source counts in the disc of M 31. The cumulative luminosity functions show a distinct flattening in the X-ray luminosity L<sub>X</sub> interval 37.0 <~ log L<sub>X</sub> erg s<sup>-1</sup> <~ 37.5. Such a feature may also be present in the X-ray populations of several other galaxies, but at a much lower statistical significance. The authors investigate the number of AGN present in their source list and find that, above L<sub>X</sub> ~1.4 x 10<sup>36</sup> erg s<sup>-1</sup>, the observed population is statistically dominated by the point source population of M 31. This table was created by the HEASARC in October 2009 based on the electronic version of Table A1 from the reference paper which was obtained from the CDS (their catalog J/A+A/495/733 file tablea1.dat. This is a service provided by NASA HEASARC .

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