12:00–1:00 pm ERC 401
Host: Anirudh Chiti
Nathan Sandford (UC Berkeley) "Stellar Chemistry in the Faintest and Farthest Local Group Galaxies"
Ultra-faint dwarfs (UFDs) are the oldest, lowest mass, and most metal-poor galaxies in the Local Group, and the chemistry of their stellar populations encode a wide range of astrophysical insight on everything from the composition of dark matter to the physics of star formation, stellar evolution, and chemical enrichment in the early universe. Here I demonstrate how a one-zone chemical evolution model can constrain key aspects of low-mass galaxy evolution from the stellar metallicity distribution function of the pre-reionization era UFD Eridanus II (Eri II). Specifically, I provide evidence that Eri II formed the vast majority of its stars over a short (~300 Myr) and inefficient (SFE ~ 0.04 Gyr-1) period of star formation during which the galaxy experienced incredibly large gas outflows. In addition, I will discuss the prospects of performing detailed multi-element chemical evolution studies in Eri II and other distant UFDs—including those soon-to-be-discovered by upcoming wide-area imaging surveys (e.g., Roman, Rubin)—which will remain beyond the reach of traditional high-resolution spectroscopic follow-up but *will* be accessible by lower-resolution (R < 10,000) spectrographs on next-generation facilities.
Nathan Sandford: Nathan is a PhD student at UC Berkeley working on the evolution of low-mass galaxies in our Local Group, using observational data, chemical evolution models, and stellar atmosphere and evolution models.
