Galactic Archaeology with the Coldest Stars and Brown Dwarfs

Large-scale photometric, spectroscopic, and astrometric surveys have revolutionized our understanding of the Milky Way and its satellite systems. Nearly all of this work has made use of red giants and FGK dwarfs as tracers of Galactic structure and evolution, but greater insight can emerge from the Milky Way's lowest mass stars and brown dwarfs, the so-called ultracool dwarfs.

In this talk I will motivate the scientific potential of using ultracool dwarfs for Galactic archaeology, driven by their abundance, longevity, chemcial stability, and long-term stability (stars) or continuous evolution (brown dwarfs).  I will then focus on our recent discoveries of metal-poor brown dwarfs in the thick disk and halo in both local and deep surveys, and in globular clusters, all of which highlight the need for renewed attention to proper modeling of metallicity dependence in evolution and low-temperature atmospheric chemistry.  Finally, I will present predictions for ultracool dwarf discovery in forthcoming surveys using Euclid, LSST, and the Nancy Grace Roman Space Telescope.

Speaker: Adam Burgasser, UC San Diego