Abstract:
A major frontier in constructing a coherent view of cosmic history is to locate and study galaxies at z ~ 5 – 20, spanning the era from the formation of the first galaxies to the end of the reionization of the intergalactic hydrogen. Over the past few years, the James Webb Space Telescope (JWST) has delivered unprecedented insight into the nature of the earliest galaxies and the process of cosmic reionization. In this talk, I will present my research based on JWST spectroscopy of galaxies at z > 5, highlighting what these observations reveal about the timeline and the morphology of reionization, as well as the star formation histories, stellar populations, and chemical enrichment of galaxies during the first few hundred million years after the Big Bang.
