Description
Various solutions have been proposed to solve the high-redshift `bright galaxy problem', such as more efficient star formation, bursty star formation, and variable initial mass functions. While equally interesting, each scenario must also differ in how these stellar populations couple to the interstellar medium (ISM) through stellar feedback. In this talk, I will present first results from the MEGATRON suite of high-resolution cosmological radiation hydrodynamical zoom simulations which for the first time feature non-equilibrium chemistry and heating/cooling processes coupled to on-the-fly radiative transfer.
Each simulation explores one of these high-redshift star formation scenarios, coupled to detailed prescriptions for the formation, evolution, and feedback from population II and III stars, including: stellar winds, supernovae, and hypernovae.
Using these simulations, I will discuss the impact that these different star-formation scenarios have on the chemical evolution and phase structure of the ISM. Furthermore, using the unique capabilities of the simulations, I will trace these differences through to their impacts on direct observables: such as line ratios and diagnostic diagrams, C/O and N/O abundances, mass-metallicity relations, ionizing efficiencies, and UV continuum slopes. At each step, results will be contextualized alongside the latest JWST observations. All of this will begin to build directly falsifiable predictions through quantities which are already being directly measured at high-redshift with JWST, allowing us to better understand star-formation processes in the early universe.
