We have performed spectral analyses of all known Wolf-Rayet stars (single or binary) in the SMC. For this purpose, we have employed the Potsdam Wolf-Rayet (PoWR) model atmosphere code. For the 11 WR stars of the nitrogen sequence (WN), we calculated four grids of models with different hydrogen abundances. Furthermore, we established a series of O-star models, in order to construct the composite spectra of WN+O binaries. The only WO-type (i.e. oxygen-sequence WR) star in the SMC was also analyzed with the help of an adequate grid of models. The preliminary results are in a rough agreement with the expectation, considering the lower mass loss in the SMC's metal-poor environment. In conflict with the evolutionary models is the high hydrogen abundance found in the single WN stars. The low luminosity of one WN star (SMC AB 2) is also not explainable.
Bulletin de la Societe Royale des Sciences de Liege
- Pub Date:
- January 2011