Reference : X-Ray Emission from Massive Stars in Cyg OB2
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
X-Ray Emission from Massive Stars in Cyg OB2
Rauw, Gregor [Université de Liège - ULiège > > >]
Nazé, Yaël mailto [Université de Liège > > Groupe d'astrophysique des hautes énergies (GAPHE) >]
Wright, N. J. [Smithsonian Astrophysical Observatory, Cambridge, USA; Centre for Astrophysics Research, University of Hertfordshire, Hatfield, UK]
Drake, J. J. [Smithsonian Astrophysical Observatory, Cambridge, USA]
Guarcello, M. G. [Smithsonian Astrophysical Observatory, Cambridge, USA]
Prinja, R. K. [Department of Physics and Astronomy, University College London, UK]
Peck, L. W. [Department of Physics and Astronomy, University College London, UK]
Albacete Colombo, J. F. [Centro regional Zona Atlántica, Universidad Nacional del Comahue, Viedma, Argentina]
Herrero, A. [Instituto de Astrofísica de Canarias, Universidad de La Laguna, La Laguna, Spain]
Kobulnicky, H. A. [Department of Physics and Astronomy, University of Wyoming, Laramie, USA]
Sciortino, S. [INAF—Osservatorio Astronomico di Palermo, Italy]
Vink, J. S. [Armagh Observatory, College Hill, Armagh, UK)]
Astrophysical Journal Supplement Series
[en] open clusters and associations: individual: Cyg OB2 ; stars: early-type ; stars: Wolf–Rayet ; X-rays: stars
[en] We report on the analysis of the Chandra-ACIS data of O, B, and WR stars in the young association Cyg OB2. X-ray spectra of 49 O-stars, 54 B-stars, and 3 WR-stars are analyzed and for the brighter sources, the epoch dependence of the X-ray fluxes is investigated. The O-stars in Cyg OB2 follow a well-defined scaling relation between their X-ray and bolometric luminosities: log(Lx/Lbol)=-7.2+/- 0.2. This relation is in excellent agreement with the one previously derived for the Carina OB1 association. Except for the brightest O-star binaries, there is no general X-ray overluminosity due to colliding winds in O-star binaries. Roughly half of the known B-stars in the surveyed field are detected, but they fail to display a clear relationship between Lx and Lbol. Out of the three WR stars in Cyg OB2, probably only WR 144 is itself responsible for the observed level of X-ray emission, at a very low log(Lx/Lbol)=-8.8+/- 0.2. The X-ray emission of the other two WR-stars (WR 145 and 146) is most probably due to their O-type companion along with a moderate contribution from a wind–wind interaction zone.

File(s) associated to this reference

Fulltext file(s):

Open access
1401.8098v1.pdfAuthor preprint652.56 kBView/Open

Bookmark and Share SFX Query

All documents in ORBi are protected by a user license.