Studying the Epoch of Reionization with the DREaM Synthetic Galaxy Catalogs

A major event in cosmic history is the epoch of reionization (EoR), in which neutral hydrogen became reionized. This process appears to have occurred between redshifts 6 and 10, and is likely due to ultraviolet radiation from the earliest galaxies. However, data at these high redshifts is limited, and there are still many questions about the sources, timeline, and topology of reionization. Extragalactic surveys with the James Webb Space Telescope (JWST) and the Nancy Grace Roman Space Telescope (Roman) will provide extraordinary datasets of high-redshift galaxies during the EoR. In preparation for these upcoming surveys, we have created the publicly available Deep Realistic Extragalactic Model (DREaM) galaxy catalogs, designed to simulate realistic galaxy populations to redshifts z<12 and galaxy masses M> 10⁵M_☉. Using these synthetic catalogs, we have made preliminary predictions for the science returns of a Roman UDF, and forecasts of the ability of JWST and Roman to constrain the EoR.