Radial velocities, dynamics of stars and nebulosities with GAIA and VLT-GIRAFFE

GEPI, Observatoire de Paris, CNRS, Universite´ Paris Diderot; place Jules Janssen 92195 Meudon Cedex, FranceThe dates of receipt and acceptance should be inserted laterKey words Magellanic Clouds – Galaxy: kinematics and dynamics – ISM: b ubbles – stars: kinematics – methods: dataanalysisThis document is divided in two parts. The first part deals wit h the radial velocities (RV) distributions for B-type starsand nebulosities observed with the VLT-GIRAFFE in the Largeand Small Magellanic Clouds towards the open clustersNGC2004 and NGC330. Thanks to the resolution of GIRAFFE spectra, we found that the RV distribution for the nebu-losities in the LMC is bi-modal. This bi-modality can be interpreted, in term of dynamics, by the expansion of the LMC4superbubble. The second part deals with the GAIA space mission and the determination of the radial velocities by us-ing Radial Velocity Spectrometer (RVS) spectra. The methods to determine the radial velocities are presented as well aspreliminary results on simulated RVS spectra.