Title: The Production and Dispersal of Heavy Elements in the Early Universe

Abstract:       In the first billion years after the Big Bang, early generations of stars produced light which ionized intergalactic gas, and the first heavy elements of the periodic table via nuclear fusion and neutron capture. Infrared observations of quasars in this epoch constrain both of these processes, by (a) timing the phase transition of hydrogen ionization, and (b) measuring chemical abundances in very low-density gas polluted by carbon, oxygen, magnesium, iron, and other elements. I will review selected measurements of early quasars, focusing on the enrichment and ionization of heavy elements, and describe new observations with the James Webb Space Telescope that provide our first view of galaxies near where these elements were produced. I will also discuss how we aim to expand this frontier even further with anticipated instruments and giant telescopes.

Host: Rongmon Bordoloi