The structure of our Galaxy
Résumé
Tracing the spiral structure of our Galaxy requires to identify and position the star-forming complexes. Each complex can be seen as a parental molecular cloud with associated ionised hydrogen, young stars and young clusters. The analysis of the ionised gas at Halpha wavelength (diffuse emission as well as discrete HII regions) is essential to associate the radio sources to their molecular parental cloud, using velocity and spatial similarity. In parallel, the exciting stars of the ionised gas make the link between the velocity of the complex and the stellar distance. In this framework we have performed a Halpha survey of the southern Milky Way (with a scanning Fabry-Perot interferometer). Coupled with multiwavelengh data, this allowed us to establish a star-forming complexes catalogue from which we traced the spiral structure and kinematic (rotation curve and circular velocity departures) of our Galaxy.