Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-13T05:27:58.063Z Has data issue: false hasContentIssue false
  • English
  • Français

X-ray spectral diagnostics of activity in massive stars

Published online by Cambridge University Press:  12 July 2011

David H. Cohen ,
Emma E. Wollman  and
Maurice A. Leutenegger
David H. Cohen
Affiliation:
Department of Physics and Astronomy, Swarthmore College, 500 College Ave., Swarthmore, Pennsylvania, 19081, USA email: cohen@astro.swarthmore.edu
Emma E. Wollman
Affiliation:
Department of Physics, California Institute of Technology, Pasadena, California, 91125, USA email: ewollman@caltech.edu
Maurice A. Leutenegger
Affiliation:
NASA/Goddard Spaceflight Center, Code 662, Greenbelt, Maryland, 20771, USA email: maurice.a.leutenegger@nasa.gov
Rights & Permissions [Opens in a new window]

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.

X-rays give direct evidence of instabilities, time-variable structure, and shock heating in the winds of O stars. The observed broad X-ray emission lines provide information about the kinematics of shock-heated wind plasma, enabling us to test wind-shock models. And their shapes provide information about wind absorption, and thus about the wind mass-loss rates. Mass-loss rates determined from X-ray line profiles are not sensitive to density-squared clumping effects, and indicate mass-loss rate reductions of factors of 3 to 6 over traditional diagnostics that suffer from density-squared effects. Broad-band X-ray spectral energy distributions also provide mass-loss rate information via soft X-ray absorption signatures. In some cases, the degree of wind absorption is so high, that the hardening of the X-ray SED can be quite significant. We discuss these results as applied to the early O stars ζ Pup (O4 If), 9 Sgr (O4 V((f))), and HD 93129A (O2 If*).

Keywords

line: formationshock wavesstars: windsoutflowsX-rays: stars
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 6 , Symposium S272: Active OB stars: structure, evolution, mass loss, and critical limits , July 2010 , pp. 348 - 353
Copyright
Copyright © International Astronomical Union 2011

References

Cohen, D. H., Leutenegger, M. A., Wollman, E. E., Zsargó, J. et al. 2010, MNRAS, 405, 2391Google Scholar
Feldmeier, A., Puls, J. & Pauldrach, A. W. A. 1997, A&A, 322, 878Google Scholar
Lamers, H. J. G. L. M. & Leitherer, C. 1993, ApJ, 412, 771Google Scholar
Leutenegger, M. A., Cohen, D. H., Zsargó, J., Martell, E. M. et al. 2010, ApJ, 719, 1767CrossRefGoogle Scholar
Markova, N., Puls, J., Repolust, T., & Markov, H. 2004, A&A, 413, 693Google Scholar
Oskinova, L. M., Feldmeier, A., & Hamann, W.-R. 2006, MNRAS, 372, 313Google Scholar
Owocki, S. P., Castor, J. I., & Rybicki, G. B. 1988, ApJ, 335, 914Google Scholar
Owocki, S. P. & Cohen, D. H. 2001, ApJ, 559, 1108Google Scholar
Puls, J., Kudritzki, R.-P., Herrero, A., Pauldrach, A. W. A. et al. 1996, A&A, 305, 171Google Scholar
Puls, J., Markova, N., Scuderi, S., Stanghellini, C. et al. 2006, A&A, 454, 625Google Scholar
Repolust, T., Puls, J., & Herrero, A. 2004, A&A, 415, 349Google Scholar
Runacres, M. C. & Owocki, S. P. 2002, A&A, 381, 1015Google Scholar
Smith, R. K., Brickhouse, N. S., Liedahl, D. A., & Raymond, J. C. 2001, ApJ (Letters), 556, L91CrossRefGoogle Scholar
Taresch, G., Kudritzki, R. P., Hurwitz, M., & Bowyer, S. et al. 1997, A&A, 321, 531Google Scholar