A New Generation of Absorption Spectroscopy Experiments Probing the Epoch of Reionization

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

In the early universe, much of the gas between galaxies was neutral hydrogen. The early generations of stars, galaxies, and black holes emitted radiation that ionized this gas. The period of time when this occurred is known as the epoch of reionization. The history of reionization sheds light on the nature and evolution of the early universe. This project will use observations of the most distant quasars to study the ionization state of the hydrogen gas between us and the quasars. The project will also study the enrichment of the gas by heavier elements produced in the first stars. The project will also support one graduate student, partially support a post-doc, and provide summer stipends for two undergraduates from Hispanic Serving Institutions in years 1 and 2. The project will also provide indirect support for the maintenance and distribution of the PypeIt software package for spectroscopic data reduction. The project will use spectroscopic data from the Keck telescope for 200 quasar sightlines to study the intergalactic medium (IGM). The quasars are all at redshifts greater than 6. The spectroscopic analysis will allow for the identification of the local ionization status of the IGM as well as identifying evidence of enrichment of the IGM with metals from the first supernovae. By identifying the local ionization status around the quasars, the project will also provide a history of the radiative history of the quasar -- thus allowing for a better understanding of how these supermassive black holes grew to such large masses within 800 Myr after the Big Bang. The project will conduct end-to-end analyses encompassing observations, theoretical modeling, state-of-the-art simulations, and Bayesian inference to provide a solid methodological footing for study of the epoch of reionization. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.