Journal article
Acceleration efficiency in line-driven flows
The Astrophysical journal, Vol.434(2), pp.684-694
10/20/1994
DOI: 10.1086/174769
Abstract
We reexamine the physics of flow driving by line scattering of a continuum radiation source to determine the degree to which such line scattering can heat as well as accelerate the flow. Within the framework of the Sobolev theory for line transfer, we argue that the finite thermal width of the line scattering profile can lead to a significant 'Doppler heating' via photon frequency redistribution within a Sobolev resonance layer. Quantitative computation of this heating shows, however, that it is largely canceled by a corresponding cooling by the diffuse radiation. The resulting reduction in net Doppler heating or cooling means that the overall effect is only of limited importance in the energy balance of line-driven stellar winds. Through simple scaling relations, we compare the effect to other competing heating or cooling terms, including the ion-drag frictional heating recently discussed by Springmann and Pauldrach. We also provide a physical explanation of the unexpected cooling effect, and comment that its near cancellation of the anticipated heating provides another example of the tendency for ideal Sobolev theory to apply to a higher order than expected.
Details
- Title: Subtitle
- Acceleration efficiency in line-driven flows
- Creators
- Kenneth G. Gayley - University of DelawareStanley P. Owocki - University of Delaware
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal, Vol.434(2), pp.684-694
- DOI
- 10.1086/174769
- ISSN
- 0004-637X
- eISSN
- 1538-4357
- Language
- English
- Date published
- 10/20/1994
- Description audience
- PUBLIC
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984428775102771
Metrics
1 Record Views