Constraints on wind clumping from the empirical mass-loss vs. metallicity relation for early-type stars

  • We present the latest results on the observational dependence of the mass-loss rate in stellar winds of O and early-B stars on the metal content of their atmospheres, and compare these with predictions. Absolute empirical rates for the mass loss of stars brighter than 10$^{5.2} L_{\odot}$, based on H$\alpha$ and ultraviolet (UV) wind lines, are found to be about a factor of two higher than predictions. If this difference is attributed to inhomogeneities in the wind this would imply that luminous O and early-B stars have clumping factors in their H$\alpha$ and UV line forming regime of about a factor of 3--5. The investigated stars cover a metallicity range $Z$ from 0.2 to 1 $Z_{\odot}$. We find a hint towards smaller clumping factors for lower $Z$. The derived clumping factors, however, presuppose that clumping does not impact the predictions of the mass-loss rate. We discuss this assumption and explain how we intend to investigate its validity in more detail.

Download full text files

Export metadata

Additional Services

Share in Twitter Search Google Scholar Statistics
Metadaten
Author:A. de Koter, J. S. Vink, L. Muijres
URN:urn:nbn:de:kobv:517-opus-17736
Document Type:Conference Proceeding
Language:English
Year of Completion:2007
Publishing Institution:Universität Potsdam
Release Date:2008/04/25
RVK - Regensburg Classification:US 1999.07
Organizational units:Extern / Extern
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 52 Astronomie / 520 Astronomie und zugeordnete Wissenschaften
Collections:Universität Potsdam / Tagungsbände/Proceedings (nicht forlaufend) / Clumping in hot-star winds: International Workshop, Potsdam, Germany, 18. - 22. June 2007
Universität Potsdam / Tagungsbände/Proceedings (nicht forlaufend) / Clumping in hot-star winds: International Workshop, Potsdam, Germany, 18. - 22. June 2007 / Talks and Discussions (in alphabetical order)
Universität Potsdam / Tagungsbände/Proceedings (nicht forlaufend) / Clumping in hot-star winds: International Workshop, Potsdam, Germany, 18. - 22. June 2007 / Talks and Discussions (organized by sections) / Spectroscopy and mass loss diagnostic: observations
Licence (German):License LogoKeine Nutzungslizenz vergeben - es gilt das deutsche Urheberrecht
Notes extern:
The complete edition of the proceedings "Clumping in hot-star winds" is available:
urn:nbn:de:kobv:517-opus-13981