Speaker: Dr. Julian B. Muñoz, The University of Texas at Austin
Date/Time: September 27, 2024 / 12 noon central.
Location: Beckman Institute, RM 5602
Zoom: https://illinois.zoom.us/j/82318062756?pwd=M3g1MFF6cytsOWFEbmU0UW1XWVoxQT09
Title: Cosmological puzzles from early JWST observations
Abstract: The launch of the James Webb Space Telescope (JWST) has ignited a revolution in our understanding of the early universe. Its exquisite infrared capabilities have allowed observers to find galaxies at higher redshifts and measure their stellar properties better than ever before. I will describe how, intriguingly, observations in these different arenas appear to be in tension with our models. I will discuss the higher-than-expected abundance of early (z>9) galaxies in JWST, and show how clustering measurements are key for understanding how these galaxies formed. Then, I will show how recent JWST determinations of the ionizing properties of the first galaxies are in tension with CMB and Lyman-alpha forest observations. If time allows, I will discuss the road ahead with future observatories including 21-cm telescopes.