Abstract
Radiation from the first stars and galaxies initiated the dramatic phase transition marking an end to the cosmic dark ages. The emission and absorption signatures from the Lyman-alpha (Lyα) transition of neutral hydrogen have been indispensable in extending the observational frontier for high-redshift galaxies into the epoch of reionization. Lyα radiative transfer provides clues about the processes leading to Lyα escape from individual galaxies and the subsequent transmission through the intergalactic medium. Cosmological simulations incorporating Lyα radiative transfer enhance our understanding of fundamental physics by supplying the inferred spectra and feedback on the gas.
In this dissertation talk, I will give an overview of my research carried out at UT Austin, including my new resonant discrete diffusion Monte Carlo (rDDMC) method designed to break the efficiency barrier of Monte Carlo Lyα radiative transfer in the high optical depth regime. Such efficient and robust algorithms will enable fully coupled 3D Lyα radiation hydrodynamics in the near future. I will also discuss recent advances in Lyα modeling based on state-of-the-art simulations and observational insights. As a case study I will present post-processing results of cosmological "zoom-in" simulations of z > 5 galaxies created with the hydrodynamics code GIZMO under the framework of Feedback In Realistic Environments (FIRE), demonstrating that the observational signatures from the same galaxy can vary significantly depending on redshift and viewing angle.
