Speaker
Description
The growth of galaxies across cosmic time is regulated by a variety of processes, such as the formation of stars from the infall of new gas, the processing of gas into heavier elements within stars, and the release of this enriched material when stars die. By exploring the chemical content of galaxies at different cosmic epochs, we can constrain the mechanisms by which galaxies evolve. In addition, specific element abundance ratios can be used to constrain the rate of enrichment via different physical processes (e.g., CCSNe vs Typa Ia SNe), yielding insights into star-formation and chemical enrichment timescales. Previously, almost all observations at high redshifts (z>2) were sensitive only to the oxygen abundance (O/H). However, new developments in the analysis of deep UV spectra now enable the measurement of iron abundances (Fe/H) at these redshifts. In this talk, I will present measurements of the O/Fe ratio for star-forming galaxies at z=3.5. Our results show evidence for enhanced O/Fe ratios (relative to the solar value) as expected for young systems in the early Universe. I will also present a comparison between our observations at z=3.5 and stellar archaeology measurements of stars in the Milky Way. Finally, I will discuss the implications of our results with respect to modelling the stellar populations of galaxies at z > 2.
