Far Ultraviolet Spectroscopic Explorer Observations of the Stellar Winds of Two O7 Supergiants in the Magellanic Clouds
Abstract
We compare the stellar wind features in far-UV spectra of Sk -67°111, an O7 Ib(f) star in the LMC, with Sk 80, an O7 Iaf+ star in the SMC. The most striking differences are that Sk 80 has a substantially lower terminal velocity, much weaker O VI absorption, and stronger S IV emission. We have used line-blanketed, hydrodynamic, non-LTE atmospheric models to explore the origin of these differences. The far-UV spectra require systematically lower stellar temperatures than previous determinations for O7 supergiants derived from plane-parallel, hydrostatic models of photospheric line profiles. At these temperatures, the O VI in Sk -67°111 must be due primarily to shocks in the wind.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2000
- DOI:
- 10.1086/312787
- arXiv:
- arXiv:astro-ph/0005039
- Bibcode:
- 2000ApJ...538L..43F
- Keywords:
-
- Stars: Early-Type;
- Stars: Individual: Alphanumeric: Sk -67°111;
- Stars: Individual: Alphanumeric: Sk 80;
- Stars: Winds;
- Outflows;
- Astrophysics
- E-Print:
- 10 pages, 2 figures. AASTeX preprint format. This paper will appear in a special issue of Astrophysical Journal Letters devoted to the first scientific results from the FUSE mission