Dr. Pratik Gandhi (Yale)

The nature of the first stars (or “popIII” stars), including their IMF, supernovae, and nucleosynthetic yields, remains a key astrophysical mystery. Although JWST has opened up new windows into the extremely high-redshift Universe, it remains almost impossible to directly observe popIII stars in the earliest galaxies. Fortunately, the lowest-mass galaxies in the Local Group provide a powerful alternative: these galaxies are relics of cosmic dawn, and through their star formation histories (SFHs) and elemental abundances act as “fossil records” of the early Universe. I will present my work modelling the feedback from popIII stars in new FIRE-3 zoom-in simulations of low-mass galaxies, in comparison with elemental abundance measurements of actual Local Group galaxies. This work will inform HST/JWST observations of both resolved local stellar populations as well as high-redshift galaxies, and shed light on a hitherto unseen part of the cosmic timeline.