Lamiya Mowla

Prof. Lamiya Mowla is an assistant professor in the Department of Physics and Astronomy at Wellesley College.

Talk title: “Exploring the Co-Evolution of Star Clusters and Galaxies Since Cosmic Dawn”

Abstract: The most distant galaxies observed date back to when the Universe was only 5% of its current age, with progenitors of galaxies like the Milky Way being about 10,000 times less massive. Using JWST and the magnification provided by gravitational lensing, these low-mass galaxies can be detected and studied in detail. I will present JWST observations of the “Firefly Sparkle,” a strongly lensed galaxy at ( z = 8.3 ) featuring massive star clusters cocooned in a diffuse arc, showcasing characteristics of a young, gas-rich galaxy in the early stages of formation. The unresolved clusters display exceptionally high surface densities, surpassing those of Milky Way globular clusters and nearby young star clusters, along with nebular-dominated spectra, low metallicity, high gas density, and elevated electron temperatures, suggesting a top-heavy initial mass function (IMF). These observations provide the first spectrophotometric view of a typical galaxy at Cosmic Dawn, highlighting JWST’s capability to investigate the co-evolution of galaxies and star clusters. I will also discuss plans to expand this work using future JWST cluster observations, aiming to deepen our understanding of the evolution of galaxy evolution.