The structure of the winds from Wolf-Rayet stars as determined from observations of the infrared continua.
Abstract
An attempt is made to derive the density structure of Wolf-Rayet winds from infrared observations. Free-free emission from gas in radiative equilibrium is assumed to be the source of the infrared excess, and the density distribution is approximated by piecewise power laws. Wolf-Rayet stars that exhibit a 'turnover' in the infrared spectrum require models with a steep density drop at several stellar radii; this implies a rapid acceleration of the flow at large distances from the stellar core. Models have been constructed to fit the infrared excess of HD 50896, a slightly reddened WN5 star. They indicate that the extended density region has an electron-scattering optical depth of at least 0.7 and is at nearly constant velocity or decelerating. A possible alternative to these models is one which combines a coronal zone in an accelerating wind.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1977
- DOI:
- 10.1086/155342
- Bibcode:
- 1977ApJ...215..155H
- Keywords:
-
- Density Distribution;
- Hot Stars;
- Infrared Astronomy;
- Infrared Spectra;
- Stellar Models;
- Stellar Winds;
- Wolf-Rayet Stars;
- Black Body Radiation;
- Electron Scattering;
- Spectral Energy Distribution;
- Stellar Spectrophotometry;
- Astrophysics