2001/04/20 by R. Supper, G. Hasinger, W. H. G. Lewin +6 · 6 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1051/0004-6361:20010495
published as A&A 373, 63-99 (2001) · 39 pages, 3 figures (figure 2 on page 5 should be printed in color). Accepted (03.04.2001) for publication in A&A
arxiv created 2001/04/20 · openalex publication_date 2001/07/01 · arxiv updated 2009/12/01 · openalex created_date 2020/11/23 · openalex updated_date 2026/08/01
This paper reports the results of the analysis of the second ROSAT PSPC survey of M 31 performed in summer 1992. We compare our results with those of the first survey, already published in Supper et al.([CITE]). Within the ~ field of view, 396 individual X-ray sources are detected in the second survey data, of which 164 are new detections. When combined with the first survey, this result in a total of 560 X-ray sources in the field of M 31. Their (0.1 keV-2.0 keV) fluxes range from to , and of these 560 sources, 55 are tentatively identified with foreground stars, 33 with globular clusters, 16 with supernova remnants, and 10 with radio sources and galaxies (including M 32). A comparison with the results of the Einstein M 31 survey reveals 491 newly detected sources, 11 long term variable sources, and 7 possible transient sources. Comparing the two ROSAT surveys, we come up with 34 long term variable sources and 8 transient candidates. For the M 31 sources, the observed luminosities range from to . The total (0.1 keV-2.0 keV) luminosity of M 31 is , distributed approximately equally between the bulge and disk. Within the bulge region, the luminosity of a possible diffuse component combined with faint sources below the detection threshold is . An explanation in terms of hot gaseous emission leads to a maximum total gas mass of .