Mass loss rate determination of southern OB stars

Citation
P. Benaglia et al., Mass loss rate determination of southern OB stars, ASTRON ASTR, 372(3), 2001, pp. 952-962
Citations number
59
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Space Sciences
Journal title
ASTRONOMY & ASTROPHYSICS
ISSN journal
1432-0746 → ACNP
Volume
372
Issue
3
Year of publication
2001
Pages
952 - 962
Database
ISI
SICI code
1432-0746(200106)372:3<952:MLRDOS>2.0.ZU;2-C
Abstract
A sample of OB stars (eleven Of, one O and one B supergiant) has been surve yed with the Australia Telescope Compact Array at 4.8 and 8.64 GHz with a r esolution of similar to2"-4". Five stars were detected; three of them have negative spectral indices, consistent with non-thermal emission, and two ha ve positive indices. The thermal radiation from HD 150135 and HD 163181 can be explained as coming from an optically thick ionized stellar wind. The n on-thermal radiation from CD-47 degrees 4551, HD 124314 and HD 150136 possi bly comes from strong shocks in the wind itself and/or in the wind collidin g region if the stars have a massive early-type companion. The percentage o f non-thermal emitters among detected O stars has increased up to similar t o 50%. The Of star HD 124314 clearly shows flux density variations. Mass lo ss rates (or upper limits) were derived for all the observed stars and the results compared with non-radio measurements and theoretical predictions.