Star formation in the first galaxies
The ignition of the first sources of light marked the end of the cosmic dark ages, an era when the Universe transitioned from the relatively simple conditions following the Big Bang to the complex tapestry of dark matter, baryons, and pervasive cosmic radiation fields we see today. To better understand this uncharted cosmic epoch, we primarily utilize hydrodynamical, N-body simulations to model the assembly of the first galaxies at redshifts greater than ten and the stars that form within them. These simulations begin from cosmological initial conditions, employ a robust, non-equilibrium chemo-thermodynamic model, and take advantage of adaptive-grid-refinement to probe the multi-scale, complex process of star formation from ab initio principles. We explore the consequences that metal enrichment has on the process of star formation, confirming the presence of a critical metallicity for low-mass star formation. To assess the observational prospects of these primeval stellar populations with next-generation telescopes, like the James Webb Space Telescope, we constrain the star formation efficiency of both metal-enriched and metal-free star formation in a typical first galaxy. We also resolve the formation of individual metal-enriched stars in simulations that ultimately began from cosmological scales, allowing meaningful comparisons between our simulations and the recently discovered ultra-faint dwarf satellite galaxies, the suspected analogs of the first galaxies in the local Universe.