Plenary Lectures and VIP Guests

Dr. Timothy Carleton

Abstract:

Ultra-Diffuse Galaxies represent some of the faintest galaxies that we can observe, with average surface brightnesses well below the typical sky level. They are also some of the most numerous, with thousands identified in local galaxy clusters [1]. Some are thought to hold remnants of early intense star formation, with billion-year-old stellar populations [2] and large globular cluster populations [3]. However, the evolution of these systems is not well understood, especially the tidal interactions between them and the cluster environment in which they are typically found [4]. In addition to providing insight into galaxy formation physics at small scales, study of these systems can shed light on the nature of dark matter and the connection between dark matter halos and galaxies, given their high dark matter fractions [3]. I will discuss how observations of these systems at higher redshift, possible with observations using JWST, can teach us about their formation and evolution. In particular, recent work has shown that Ultra-Diffuse Galaxies in higher redshift clusters are more similar to field dwarf galaxies (with younger stellar populations and a wider range of sizes) than older systems observed at low-z [5].