Properties of massive stars in the Tarantula Nebula

This thesis presents the quantitative analysis of massive O-type stars in the Tarantula Nebula of the Large Magellanic Cloud. The data have been collected in the context of VLT-FLAMES Tarantula Survey (VFTS), an ESO Large Programme that has obtained multi-epoch optical spectroscopy of 800 OB-type stars using the Very Large Telescope (VLT) in Chile. My thesis studies around 330 O-type stars in the VFTS. The first part of the thesis focusses on the stellar rotational properties of spectroscopic single and binary O-type stars in the Tarantula Nebula. The distribution of spin rates of massive stars is important because it is the fingerprint of their formation process, which it is not well understood, and an important ingredient for their evolution. In the second part of the thesis, the focus shifts to properties of O-type giants, bright giants, and supergiants in the VFTS. Using quantitative spectroscopy, we constrain the stellar and wind parameters, and the surface abundances of the objects in our sample. We then confront these observational constraints to the predictions of theories of the evolution of massive stars.