The Measurement of Rotation, Macroturbulence and Expansion Velocities in 0 Star Atmospheres Using Fourier Transform Analysis of Absorption Line Profiles.
Abstract
The broad absorption lines observed in the spectra of O type stars have long suggested the presence of macroscopic velocity fields. Analyzing line profiles in the Fourier transform domain, allowed a fairly unambiguous separation of the velocity fields to be made. Results show that for stars on the main sequence, little or no turbulence can be detected. For the supergiants, rotation alone cannot simultaneously reproduce the line profiles and their transforms. Macroturbulence, modeled by an isotropic Gaussian distribution of velocities, is needed to produce satisfactory agreement with observations in both domains.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- May 1977
- Bibcode:
- 1977PhDT.........3E
- Keywords:
-
- Physics: Astronomy and Astrophysics;
- Atmospheric Turbulence;
- Line Spectra;
- O Stars;
- Velocity Distribution;
- Fourier Transformation;
- Hot Stars;
- Stellar Atmospheres;
- Stellar Rotation;
- Astronomy