Reference : Hot stars observed by XMM-Newton. I. The catalog and the properties of OB stars
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
http://hdl.handle.net/2268/6224
Hot stars observed by XMM-Newton. I. The catalog and the properties of OB stars
English
Nazé, Yaël mailto [Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique observationnelle (sol et espace) >]
1-Nov-2009
Astronomy and Astrophysics
EDP Sciences
506
1055-1064
Yes (verified by ORBi)
International
0004-6361
1432-0746
Les Ulis
France
[en] X-rays: stars ; stars: early-type ; catalogs
[en] Aims: Following the advent of increasingly sensitive X-ray observatories, deep observations of early-type stars became possible. However, the results for only a few objects or clusters have until now been reported and there has been no large survey comparable to that based upon the ROSAT All-Sky Survey (RASS). <BR />Methods: A limited survey of X-ray sources, consisting of all public XMM-Newton observations (2XMMi) and slew survey data (XMMSL1), is now available. The X-ray counterparts to hot, massive stars have been searched for in these catalogs. <BR />Results: About 300 OB stars were detected with XMM-Newton. Half of them were bright enough for a spectral analysis to be possible, and we make available the detailed spectral properties that were derived. The X-ray spectra of O stars are represented well by low (<1 keV) temperature components and seem to indicate that an absorption column is present in addition to the interstellar contribution. The X-ray fluxes are well correlated with the bolometric fluxes, with a scatter comparable to that of the RASS studies and thus larger than found previously with XMM-Newton for some individual clusters. These results contrast with those of B stars that exhibit a large scatter in the L[SUB]X[/SUB] - L[SUB]BOL[/SUB] relation, no additional absorption being found, and the fits indicate a plasma at higher temperatures. Variability (either within one exposure or between multiple exposures) was also investigated whenever possible: short-term variations are far more rare than long-term ones (the former affects a few percent of the sample, while the latter concerns between one third and two thirds of the sources). <BR />Conclusions: This paper presents the results of the first high-sensitivity investigation of the overall high-energy properties of a sizable sample of hot stars. Based on observations collected with XMM-Newton, an ESA Science Mission with instruments and contributions directly funded by ESA Member States and the USA (NASA), and accessed via the 2XMMi and XMM slew survey catalogs. Tables 1 and 5 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/506/1055 Postdoctoral Researcher FNRS. Visiting astronomer, UNAM-Morelos (Mexico).
Researchers ; Professionals
http://hdl.handle.net/2268/6224
10.1051/0004-6361/200912659
http://cdsads.u-strasbg.fr/abs/2009A%26A...506.1055N
http://de.arxiv.org/abs/0908.1461

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