EDP Sciences
Free access
Volume 402, Number 2, May I 2003
Page(s) 713 - 718
Section Stellar atmospheres
DOI http://dx.doi.org/10.1051/0004-6361:20030287

A&A 402, 713-718 (2003)
DOI: 10.1051/0004-6361:20030287

On multicomponent effects in stellar winds of stars at extremely low metallicity

J. Krticka1, 2, 3, S. P. Owocki1, 4, J. Kubát3, R. K. Galloway1 and J. C. Brown1

1  Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
2  Ústav teoretické fyziky a astrofyziky PrF MU, 611 37 Brno, Czech Republic
3  Astronomický ústav, Akademie ved Ceské republiky, 251 65 Ondrejov, Czech Republic
4  Bartol Research Institute, University of Delaware, Newark, DE 19716, USA

(Received 29 November 2002 / Accepted 20 February 2003)

We calculate multicomponent line-driven wind models of stars at extremely low metallicity suitable for massive first generation stars. For most of the models we find that the multicomponent wind nature is not important for either wind dynamics or for wind temperature stratification. However, for stars with the lowest metallicities we find that multicomponent effects influence the wind structure. These effects range from pure heating to possible fallback of the nonabsorbing wind component. We present a simple formula for the calculation of metallicity for which the multicomponent effects become important. We show that the importance of the multicomponent nature of winds of low metallicity stars is characterised not only by the low density of driving ions, but also by lower mass-loss rate.

Key words: stars: mass-loss -- stars: early-type -- stars:abundances -- stars: winds, outflows

Offprint request: J. Krticka, jiri@astro.gla.ac.uk

© ESO 2003