Special Astronomy Tea Talk

Observations of the structure and dynamics of different stellar populations in the Milky Way's disk provide a unique perspective on disk formation, evolution, and dynamics. I will discuss how current and future data sets that provide detailed kinematics and elemental abundances beyond the Solar neighborhood lead to qualitatively new tests of internal and external disk evolution models. In particular, I will show recent results from a dissection into mono-abundance populations (MAPs) of the Galactic disk based on SDSS/SEGUE data. These results show that the individual components are simple, but exhibit very different spatial and kinematic structure. The MAP decomposition additionally shows that the vertical structure of the Milky Way's disk is very different from what was previously believed. I will also discuss how dynamical modeling of MAPs leads to strong new measurements of the mass distribution in the inner Milky Way.