Speaker
Description
Recent JWST observations have shed light on galaxy assembly and evolution from cosmic reionization to cosmic noon. In this talk, I will review some recent work in our group. First, we focus on [OIII]-bright galaxies at z~7. By spatially resolved studies of hundreds of these ‘Little Green Dots’, we find these galaxies exhibit compact, centrally concentrated star formation, rising star formation histories, and an outside-in growth scenario. They also show high ionizing photon production efficiencies and significant escape fractions, making them key contributors to cosmic reionization. Second, we analyze more than 40,000 galaxies across 0 < z < 4 and find a transition in galaxy assembly. At z > 2.5, galaxies cannot grow in size via only in-situ star formation, suggesting a shift from outside-in to inside-out growth. This transition highlights the interplay between star formation, gas accretion, and feedback processes. Third, we explore the correlation between gas-phase metallicity and galaxy size at 1 < z < 7. We find that gravitational potential significantly influences metal enrichment, suggesting that the baryon cycle is regulated by galaxy gravitational potential even in the early universe. Collectively, these studies provide a comprehensive view of galaxy assembly from reionization to cosmic noon, highlighting JWST observations in unraveling the complex interactions between galaxies and their CGM.
