2008/11/30 by M. Henze, W. Pietsch, F. Haberl +13 · 36 citations
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Cataclysmic variable star #Context (archaeology) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma-ray bursts and supernovae #Globular cluster #History #Light curve #Physics #Spectral line #Stars #White dwarf #astro-ph
paper · pdf · doi:10.1051/0004-6361/200811122
published in Astronomy and Astrophysics 500(2), 769-779 (EDP Sciences) · 11 pages, 9 figures, 4 tables, submitted to A&A; v2: accepted version
arxiv created 2009/04/28 · openalex publication_date 2009/04/29 · arxiv updated 2015/05/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
<i>Context. <i/>Classical novae (CNe) have been found to represent the major class of supersoft X-ray sources (SSSs) in our neighbour galaxy M 31.<i>Aims. <i/>We determine the properties and evolution of the two first SSSs ever discovered in the M 31 globular cluster (GC) system.<i>Methods. <i/>We have used XMM-Newton, <i>Chandra <i/>and <i>Swift <i/>observations of the centre region of M 31 to discover both SSSs and to determine their X-ray light curves and spectra. We performed detailed analysis of XMM-Newton EPIC PN spectra of the source in Bol 111 (SS1) using blackbody and NLTE white dwarf (WD) atmosphere models. For the SSS in Bol 194 (SS2) we used optical monitoring data to search for an optical counterpart.<i>Results. <i/>Both GC X-ray sources were classified as SSS. We identify SS1 with the CN M31N 2007-06b recently discovered in the M 31 GC Bol 111. For SS2 we did not find evidence for a recent nova outburst and can only provide useful constraints on the time of the outburst of a hypothetical nova.<i>Conclusions. <i/>The only known CN in a M 31 GC can be identified with the first SSS found in a M 31 GC. We discuss the impact of our observations on the nova rate for the M 31 GC system.