April 15
Three years of searching for the most distant galaxies with JWST and what have we learned so far?
Speaker: Dr. L. Y. Aaron Yung, STScI
Abstract: The superb capabilities of JWST have extended our view into the ultra-high-redshift universe (z>12). Among the numerous scientific discoveries enabled by JWST, early deep extragalactic observations have unexpectedly revealed an abundance of massive galaxies, posing significant challenges to conventional galaxy formation models and cosmological simulations. To address this cosmic puzzle, we employ well-established galaxy formation models in conjunction with state-of-the-art cosmological simulations to explore the physical mechanisms that enabled extremely rapid star formation in the early universe. We have investigated and quantified the impact of various sources of uncertainty, including a potentially evolving mass-to-light ratio driven by changes in the IMF and UV variability, as well as field-to-field variance and uncertainties associated with photometric redshifts. I will also present a series of recent results from semi-analytic and empirical models that address the physical origins of the emerging ultra-high-redshift galaxy population and their physical properties.
Host: Ankita Bera