Mass loss rate determinations of southern OB stars
A sample of OB stars (eleven Of, one O and one B supergiant) has been surveyed with the Australia Telescope Compact Array at 4.8 and 8.64 GHz with a resolution of ∼2"–4". Five stars were detected; three of them have negative spectral indices, consistent with non-thermal emission, and two h...
| Authors: | , , |
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| Format: | article |
| Status: | Published version |
| Publication Date: | 2001 |
| Country: | Argentina |
| Institution: | Universidad Nacional de La Plata |
| Repository: | SEDICI (UNLP) |
| Language: | English |
| OAI Identifier: | oai:sedici.unlp.edu.ar:10915/123953 |
| Online Access: | http://sedici.unlp.edu.ar/handle/10915/123953 |
| Access Level: | Open access |
| Keyword: | Ciencias Astronómicas stars: early-type stars: mass loss stars: winds, outflows radio continuum: stars |
| Summary: | A sample of OB stars (eleven Of, one O and one B supergiant) has been surveyed with the Australia Telescope Compact Array at 4.8 and 8.64 GHz with a resolution of ∼2"–4". Five stars were detected; three of them have negative spectral indices, consistent with non-thermal emission, and two have positive indices. The thermal radiation from HD 150135 and HD 163181 can be explained as coming from an optically thick ionized stellar wind. The non-thermal radiation from CD–47◦ 4551, HD 124314 and HD 150136 possibly comes from strong shocks in the wind itself and/or in the wind colliding region if the stars have a massive early-type companion. The percentage of non-thermal emitters among detected O stars has increased up to ∼50%. The Of star HD 124314 clearly shows flux density variations. Mass loss rates (or upper limits) were derived for all the observed stars and the results compared with non-radio measurements and theoretical predictions. |
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