Multicomponent radiatively driven stellar windsII. Gayley-Owocki heating in multitemperature winds of OB stars

KRTIČKA, Jiří and Jiří KUBÁT. Multicomponent radiatively driven stellar windsII. Gayley-Owocki heating in multitemperature winds of OB stars. Astronomy and Astrophysics. Les Ulis Cedex, France: EDP Sciences, 2001, vol. 35, No 377, p. 175-191. ISSN 0004-6361.

Basic information

• Original name: Multicomponent radiatively driven stellar windsII. Gayley-Owocki heating in multitemperature winds of OB stars
• Authors: KRTIČKA, Jiří (203 Czech Republic, guarantor) and Jiří KUBÁT.
• Edition: Astronomy and Astrophysics, Les Ulis Cedex, France, EDP Sciences, 2001, 0004-6361.

Other information

• Original language: English
• Type of outcome: Article in a journal
• Field of Study: 10308 Astronomy
• Country of publisher: France
• Confidentiality degree: is not subject to a state or trade secret
• Impact factor: Impact factor: 2.790 in 2000
• RIV identification code: RIV/00216224:14310/01:00004405
• Organization unit: Faculty of Science
• Keywords in English: hydrodynamics -- stars: mass-loss -- stars: early-type -- stars: winds; outflows
• Tags: outflows
• Tags: International impact, Reviewed

Abstract

We show that the so-called Gayley-Owocki (Doppler) heating is important for the temperature structure of the wind of main sequence stars cooler than the spectral type O6. The formula for Gayley-Owocki heating is derived directly from the Boltzmann equation as a direct consequence of the dependence of the driving force on the velocity gradient. Since Gayley-Owocki heating deposits heat directly on the absorbing ions, we also investigated the possibility that individual components of the radiatively driven stellar wind have different temperatures. This effect is negligible in the wind of O stars, whereas a significant temperature difference takes place in the winds of main sequence B stars for stars cooler than B2. Typical temperature differences between absorbing ions and other flow components for such stars is of the order 103 K. However, in the case when the passive component falls back onto the star, the absorbing component reaches temperatures of order 106 K, which allows for emission of X-rays. Moreover, we compare our computed terminal velocities with the observed ones. We found quite good agreement between predicted and observed terminal velocities. The systematic difference coming from the using of the so called "cooking formula" has been removed.

Links

• GA205/01/0656, research and development project: Name: Modelování rozsáhlých obálek horkých hvězd