Properties of fast winds in hot stars in the Magellanic Clouds.

Abstract

The early-type stars in the Magellanic Clouds for which good quality high-resolution spectra with the IUE satellite exist have been studied for their stellar wind. Their P Cygni profiles in the N V, C IV, Si IV, O V, and N IV lines have been investigated with the SEI (Sobolev plus exact integration) method. Particularly good fits of the theoretical with the observed profiles were obtained in the stars Sk -675, -67 111, -67 166 of the LMC, and in Sk 80 of the SMC, which are the only stars in the sample examined (7 stars) having a single "optical" spectrum free from WR characteristics. A comparison with galactic early-type stars of the same spectral type indicates that the ratio of the M_MC_/M_MW_ in these stars is about 0.5, in qualitative agreement with the prediction of the line-radiation- driven-wind theory, considering the lower metal abundances in the Magellanic Clouds in comparison with the Milky Way early-type stars.