Nicole Drakos (UCSC): "DREaM Synthetic Galaxy Catalogs for a Roman Ultra Deep Field"


A major event in cosmic history is the epoch of reionization (EoR), in which neutral hydrogen became re-ionized. 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. JWST will revolutionize our understanding of the EoR, obtaining information on the most distant galaxies in the Universe. In a few years, the launch of the Roman Space Telescope will further increase our knowledge of the EoR. Due to Roman’s large field of view, this telescope will be able to detect enormous numbers of galaxies, minimize cosmic variance, and allow for the study of the environment around individual galaxies. Realistic synthetic galaxy catalogs are crucial to optimize the design of a Roman Ultra Deep Fiedl (UDF), understand systematics, and develop analysis tools. In this talk, I will present the publicly available Deep Realistic Extragalactic Model (DREaM) synthetic galaxy catalogs, designed to represent realistic galaxy populations to redshifts z<12 and galaxy masses M* > 105 Msol. Using these synthetic catalogs, I will present preliminary predictions for the science returns of a Roman UDF, and discuss the role of galaxy surveys in constraining the EoR.