Description
The advent of JWST has allowed us to peer further into the Universe than we've ever been able to before. With over 20 galaxies observed beyond redshift 10, we are now able to observe the formation of galaxies at a time where we still expect the formation of population III (Pop. III) stars. In this talk I will introduce the MEGATRON simulation of a Milky Way-mass galaxy at redshift 0, and its prescription for the formation of individual Pop. III stars at Cosmic Dawn. MEGATRON features a comprehensive out-of-equilibrium chemistry network of 82 species coupled to multi-frequency on-the-fly radiation transfer from stellar SEDs. This enables us to model a multi-phase ISM through accurate cooling curves, to track and resolve the chemical enrichment and ionization from stellar feedback, and generate galaxy spectra to compare with observations. We calculate spectra for all galaxies forming Pop. III stars and show that even for galaxies with large bursts of Pop. III formation, their observational signatures are much too dim to be observed with JWST. We also track Pop. III stars through particle tagging to redshift 0 and show that a significant number of Pop. III stellar remnants reside in sub halos.
