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 Sāµ 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)
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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.