The Large and Small Magellanic Clouds are priviledged environments to perform
tests of theoretical predictions at low metallicity on rotational velocities
and stellar evolution. According to theoretical predictions, the rotational
velocities of B-type stars are expected to be higher in low metallicity
(LMC/SMC) than in high metallicity (MW) environments. To verify the models, we
observed with the VLT-FLAMES 523 B and Be stars, which form, at the moment, the
largest observed sample of these kind of objects in the MCs. We first
determined the stellar fundamental parameters and we found that B and Be stars
rotate faster in the MCs than in the MW. We also determined the first
distribution of the average ZAMS rotational velocities versus the mass of Be
stars. These results indicate that the appearance of Be stars is mass-,
metallicity-, stellar evolution-, and star-formation regions-dependant.
Moreover, the recent models of Long Gamma Ray Bursts progenitors foresee
possible LGRBs progenitors at the SMC's metallicity. We confront these models
with the observed (ZAMS rotational velocities, masses) distributions of the
fastest rotators (Be and Oe stars) in our sample. Furthermore, we compare the
corresponding predicted rates from our study with observed rates of LGRBs.Comment: poster IAUS25