Stellar Streams
In recent years, numerous stellar streams have been discovered in the Milky Way halo through analysis of stellar dynamics facilitated by Gaia data. I work with the S⁵ collaboration to find and chemically characterize these building blocks of our Galaxy. The plot to the right shows abundances derived for stars in the Indus stream, the first r-process enhanced stream discovered (Hansen et al., 2021)
Ultra-Faint dwarf galaxies
With large photometric surveys like the Dark Energy Survey, the discovery of small satellite systems around the Milky Way exploded. Leaving the question of what these are: Are they dark-matter-dominated dwarf galaxies or dark-matter-free star clusters? One path to answering this question is through abundance analysis of the stars.
Left: Figure from Webber et al., 2023 showing a potential preference for high K found in stars in ultra-faint dwarf galaxies. A signature that can be used to classify the system.