Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-14T06:33:44.911Z Has data issue: false hasContentIssue false
  • English
  • Français

ASCA X-ray observations of the Wolf-Rayet stars HD 193793 and HD 93162

Published online by Cambridge University Press:  07 August 2017

S. Skinner ,
F. Nagase ,
K. Koyama ,
Y. Maeda  and
Y. Tsuboi
S. Skinner
Affiliation:
1Inst of Space & Astronautical Science, 3-1-1 Yoshinodai, Kanagawa 229, Japan
F. Nagase
Affiliation:
2 Department of Physics, Kyoto Univ., Sakyo-ku, Kyoto 606-01, Japan
K. Koyama
Affiliation:
2 Department of Physics, Kyoto Univ., Sakyo-ku, Kyoto 606-01, Japan
Y. Maeda
Affiliation:
2 Department of Physics, Kyoto Univ., Sakyo-ku, Kyoto 606-01, Japan
Y. Tsuboi
Affiliation:
2 Department of Physics, Kyoto Univ., Sakyo-ku, Kyoto 606-01, Japan

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The Japan-U.S. satellite ASCA was launched in February 1993 and provides a new capability to obtain high-resolution X-ray spectra of Wolf-Rayet stars in the 0.5 — 10 keV band. We present spectra of the wide binary HD 193793 (WC7+O4-5) obtained three months after periastron with the WC7 star in front, and of the WN7 star HD 93162 in Carina. The spectrum of HD 193793 is heavily absorbed below 2 keV by the WC7 wind and shows a prominent emission line from He-like iron at 6.7 keV. Acceptable fits were obtained using a Raymond-Smith model with kT ≈ 3 keV and non-solar abundances. In contrast, the spectrum of HD 93162 is softer and shows very little emission above ≍2 keV. The relatively low signal-to-noise precludes emission line analysis, and an acceptable spectral fit was obtained using a simple Bremsstrahlung model with kT ≍ 1.6 keV. No significant variability was detected in the X-ray light-curves of either star.

Keywords

stars: Wolf-RayetX-raysindividual: HD 193793, HD 93162
Type
Session VII - Hydrodynamics and high-energy physics of colliding winds
Information
Symposium - International Astronomical Union , Volume 163: Wolf-Rayet Stars: Binaries, Colliding Winds, Evolution , 1995 , pp. 471 - 475
Copyright
Copyright © Kluwer 1995 

References

Cash, W., Charles, P., Bowyer, S., Walter, F., Garmire, G., Riegler, G. 1980, ApJ (Letters) 238, L71 CrossRefGoogle Scholar
Koyama, K., Kawada, M., Takano, S., and Ikeuchi, S. 1990, PASJ 42, L1 Google Scholar
Koyama, K., Maeda, Y., Tsuru, T., Nagase, F., and Skinner, S. 1994, PASJ 46, L93 Google Scholar
Liedahl, D.A., Osterheld, A.L., Mewe, R., Kaastra, J.S. 1994, in: Makino, F., Inoue, H. & Ohashi, T. (eds.), New Horizons of X-Ray Astronomy (Tokyo: Universal Academy Press), in press Google Scholar
Maeder, A. 1987, A&A 173, 247 Google Scholar
Prantzos, N., Doom, C., Arnould, M., de Loore, C.W.H. 1986, ApJ 304, 695 Google Scholar
Smith, L.F., Hummer, D.G. 1988, MNRAS 230, 511 Google Scholar
Williams, P.M., van der Hucht, K.A., Pollock, A.M.T., Florkowski, D.R., van der Woerd, H., Wamsteker, W.M. 1990, MNRAS 243, 662 Google Scholar