Instabilities in Line-driven Stellar Winds. III. Wave Propagation in the Case of Pure Line Absorption
Abstract
The spatial and temporal evolution of small-amplitude velocity perturbations is examined in the idealized case of a stellar wind that is driven by pure line absorption of the star's continuum radiation. It is established that the instability in the supersonic region is of the advective type relative to the star, but of the absolute type relative to the wind itself. It is also shown that the inward propagation of information in such a wind is limited to the sound speed, in contrast to the theory of Abbott, which predicts inward propagation faster than sound. This apparent contradiction is resolved through an extensive discussion of the analytically soluble case of zero sound speed.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1986
- DOI:
- 10.1086/164586
- Bibcode:
- 1986ApJ...309..127O
- Keywords:
-
- Absorption Spectra;
- Radiative Transfer;
- Stellar Radiation;
- Stellar Winds;
- Wave Propagation;
- Acoustic Velocity;
- Continuous Spectra;
- Line Spectra;
- Stability;
- Astrophysics;
- INSTABILITIES;
- RADIATIVE TRANSFER;
- STARS: WINDS