Affiliation: University of California, Riverside

Contribution: Oral

Title: Ionization Conditions and Dust Covering Fractions of High-Redshift Galaxies from Keck and JWST Spectroscopy

Abstract: A key goal of JWST is to explore the connection between massive stars and the state of the ISM throughout cosmic history. First, I will present some analyses based on combined Keck and JWST spectroscopy that demonstrate the importance of gas density in setting the physical conditions of the ISM between redshifts z~2 to z~6, and possibly up to z~9. Second, I will present efforts to constrain the hardness of the ionizing spectrum in high-redshift galaxies using ground-based rest-UV spectra from Keck and multiple rest-optical emission lines newly accessible with JWST. Finally, I will present novel constraints on the covering fraction of dust in intermediate-redshift (z~2-4) galaxies based on multiple HI Balmer and Paschen recombination lines.

This contribution can be found here (pdf).