摘要:
   The Milky Way is a rich laboratory which we can use to explore how galaxies form and evolve and which processes shape their present states. The Gaia astrometric mission in combination with data from large spectroscopic surveys and imaging surveys are revolutionizing our understanding of our Galaxy.  In this talk, I will focus on two traditional components of the MW, the stellar halo and the bulge/bar. One of the most important discoveries brought by Gaia was that the inner halo is dominated by debris from a major merger between 8 and 11 Gyr ago. The merger was dubbed 'Gaia - Enceladus' or 'Gaia - Sausage' (GES). Using 6D phase-space information, I will show that GES is related to two stellar halo structures which have the shape of amorphous Clouds, situated at distances between 10 to 25 kpc. The Milky Way also hosts a central bulge of mass 2×10^10 𝑀⊙ representing ~20% of the baryonic content of the Galaxy. The MW bulge is one hundred times closer than that of the next nearest bulge population found in M31, therefore the most accessible for individual stars observations. I will present my parametric description of the 3D stellar density distribution of the Bulge/Bar using the VVV survey and a kinematic study of the Bulge using Gaia and the ARGOS spectroscopic survey.