AR 2410 (Archival Research)

Tue Jun 6 10:29:56 GMT 2023

Principal Investigator: Ramesh Mainali
PI Institution: NASA Goddard Space Flight Center
Investigators (xml)

Title: How efficiently do galaxies produce ionizing photons in the epoch of reionization?
Cycle: 1

Determining the role of galaxies in reionizing the Universe is a fundamental goal in galaxy evolution and cosmology. One of the key variables in reionization models is the ionizing photon production efficiency, which currently remain largely unconstrained at the epoch of reionization. Leveraging datasets from two archival ERS programs (program 1324 and 1345), we propose to investigate the ionizing photon production efficiency of both bright and faint galaxy populations in the epoch of reionization. We will directly constrain ionizing photon production efficiency via measurement of extinction corrected H-alpha luminosity and rest-frame UV continuum luminosity. This will provide, for the first time, the direct constraint on ionizing photon production efficiency at z>6, informing the ionizing photon budgets of galaxies in the reionization epoch. Additionally, we will measure how ionizing photon production efficiency evolves over cosmic time, and how it varies with galaxy properties. Together, these results will serve as crucial inputs in theoretical models mapping the timeline and topology of reionization.