Reference : X-ray Emission from the Double-binary OB-star System QZ Car (HD 93206)
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
http://hdl.handle.net/2268/98169
X-ray Emission from the Double-binary OB-star System QZ Car (HD 93206)
English
Parkin, E. R. mailto [Institut d'Astrophysique et de Géophysique, Université de Liège, 17, Allée du 6 Août, B5c, B-4000 Sart Tilman, Belgium ; School of Physics and Astronomy, The University of Leeds, Woodhouse Lane, Leeds LS2 9JT, UK ;]
Broos, P. S. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802, USA]
Townsley, L. K. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802, USA]
Pittard, J. M. [School of Physics and Astronomy, The University of Leeds, Woodhouse Lane, Leeds LS2 9JT, UK]
Moffat, A. F. J. [Département de Physique, Université de Montreal, C.P. 6128, Succ. Centre-Ville, Montreal, QC H3C 3J7, Canada]
Nazé, Yaël mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique observationnelle (sol et espace)]
Rauw, Grégor mailto [Institut d'Astrophysique et de Géophysique, Université de Liège, 17, Allée du 6 Août, B5c, B-4000 Sart Tilman, Belgium]
Oskinova, L. M. [Institute for Physics and Astronomy, University of Potsdam, 14476 Potsdam, Germany]
Waldron, W. L. [Eureka Scientific Inc., 2452 Delmer Street, Oakland, CA 94602, USA]
1-May-2011
Astrophysical Journal. Supplement Series
Univ Chicago Press
194
8
Yes
International
0067-0049
Chicago
IL
[en] hydrodynamics ; stars: early-type ; stars: individual(QZ Carinae) ; stars: massive ; stars: winds ; outflows ; X-rays: stars
[en] X-ray observations of the double-binary OB-star system QZ Car (HD 93206) obtained with the Chandra X-ray Observatory over a period of roughly 2 years are presented. The respective orbits of systems A (O9.7 I+b2 v, P [SUB]A[/SUB] = 21 days) and B (O8 III+o9 v, P [SUB]B[/SUB] = 6 days) are reasonably well sampled by the observations, allowing the origin of the X-ray emission to be examined in detail. The X-ray spectra can be well fitted by an attenuated three-temperature thermal plasma model, characterized by cool, moderate, and hot plasma components at kT ~= 0.2, 0.7, and 2 keV, respectively, and a circumstellar absorption of sime0.2 × 10[SUP]22[/SUP] cm[SUP]-2[/SUP]. Although the hot plasma component could be indicating the presence of wind-wind collision shocks in the system, the model fluxes calculated from spectral fits, with an average value of sime7 × 10[SUP]-13[/SUP] erg s[SUP]-1[/SUP] cm[SUP]-2[/SUP], do not show a clear correlation with the orbits of the two constituent binaries. A semi-analytical model of QZ Car reveals that a stable momentum balance may not be established in either system A or B. Yet, despite this, system B is expected to produce an observed X-ray flux well in excess of the observations. If one considers the wind of the O8 III star to be disrupted by mass transfer, the model and observations are in far better agreement, which lends support to the previous suggestion of mass transfer in the O8 III + o9 v binary. We conclude that the X-ray emission from QZ Car can be reasonably well accounted for by a combination of contributions mainly from the single stars and the mutual wind-wind collision between systems A and B.
http://hdl.handle.net/2268/98169
10.1088/0067-0049/194/1/8
http://adsabs.harvard.edu/abs/2011ApJS..194....8P
http://de.arxiv.org/abs/1103.0794

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