Speaker
Description
Rest-frame far-ultraviolet (FUV) observations from JWST are currently revolutionizing our understanding of the high-z galaxies that drove reionization and the mechanisms by which they accomplished it. In order to fully interpret these new observations, we must be able to carefully diagnose how properties of the neutral interstellar medium (e.g., column density, covering fraction, outflow velocity) directly relate to the absorption features produced. Using the high-S/N and high-resolution FUV spectra (1050-1800A) of 45 nearby star-forming galaxies from the CLASSY survey, we present the largest uniform and simultaneous characterization of neutral and low-ionization interstellar UV absorption lines (O I, Si II, S II, C II, Al II) across a wide range of galaxy properties. We explore correlations between neutral O I features, singly-ionized interstellar lines, and measurements made directly from H I gas, to evaluate whether they were produced by the same populations of gas. For the first time, we are able to empirically evaluate the use of simultaneous 1-component absorption-line fitting as a means to study the neutral ISM for a diverse range of galactic properties. With the challenges associated with directly observing H I at higher redshifts, we found that low-ionization absorption lines present a powerful method for tracing the neutral ISM in star-forming galaxies.
