Milky Way's Mass and Anisotropy Profiles with LAMOST/SDSS and Gaia

Galaxy halos hold clues to the formation and evolution of galaxies, but attaining such information in the Milky Way has been complicated by the halo's large spatial extent and its small number density of luminous stars, clusters, and satellites.Despite being the galaxy studied in greatest detail, there are still many probing questions needing answers and still large uncertainties in what we do know. Even a basic measurement such as the total mass of the Milky Way remains uncertain by about a factor of 50%. Two key measurements which are involved in mass estimation using halo stars are the halo density profile and the so-called orbital anisotropy beta profile -- a measure of how radial or tangential the orbits in the Milky Way halo are on average. I present two studies of the formation and evolution of galaxies through kinematical and chemical analysis of observations of the Milky Way halo. Making use of the large stellar halo samples from LAMOST, SDSS, and Gaia, I present our measured mass and anisotropy beta profiles. 

Speaker: 
Sarah Bird (NAOC)
Location: 
DoA, Rm 2907
Time: 
Mon, 2018-11-05 12:00 to 13:00