DARK-MATTER IN THE GALAXY

I will first review the evidence that our Milky Way Galaxy contains a substantial amount of dark matter, and what is known about the spatial distribution of this material, from rotation curve decompositions and from analysis of the vertical force law in the solar neighborhood. All data are consistent with no significant unidentified material in the Galactic disk, requiring that the dark matter be in a spatially-extended distribution. Brown dwarfs, or sub-stellar objects, are often discussed as possible dark-matter candidates, especially in view of the implication from nucleosynthesis calculations that dark baryons exist. The somewhat discouraging status of recent searches for brown dwarfs is reviewed, together with present understanding of the low-mass stellar initial mass function. I discuss a long-term survey of the motions and chemical abundances of Galactic stars which will provide constraints on the Galactic potential well and the history of Galaxy formation.