Using the DREaM Synthetic Galaxy Catalog to Study the Science Returns of 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. To study the galaxies thought to be responsible for reionizing the universe, we need surveys of faint, high-redshift galaxies. In particular, an Ultra-Deep Field (UDF) with Roman Space Telescope would greatly enhance our understanding of the EoR. Roman will have an incredible field of view, allowing for deep images of large areas in the sky. A Roman UDF would capture multiple reionization bubbles and allow for the study of the environment around the galaxies thought to be responsible for reionization. The creation of realistic synthetic galaxy catalogs are crucial to optimize the design of a Roman UDF, understand systematics, and develop analysis tools. In this talk, I will present the Deep Realistic Extragalactic Model (DREaM) galaxy catalogs, designed to generate realistic galaxy populations to redshifts z<12 and galaxy masses M> 105 M☉. Using these synthetic catalogs, I will present preliminary predictions for the science returns of a Roman UDF.

Speaker: Nicole Drakos (University of California, Santa Cruz)

The Roman Lecture Series is a monthly virtual lecture series focused on the scientific capabilities and technology of the Nancy Grace Roman Space Telescope, organized by Roman Mission partners.