Astronomy Colloquium / Fall 2007

James Jee

UC Davis

Dark Matter Substructures in Galaxy Clusters Revealed by Gravitational Lensing with HST/ACS

Gravitational lensing analyses of galaxy clusters with HST/ACS bring us many interesting discoveries. Among these are dark matter substructures found in some merging galaxy clusters. Thanks to the unprecedented sensitivity and resolution of HST/ACS, these substructures are well resolved and possess high significance. I will present our gravitational lensing analyses of three interesting galaxy clusters showing distinct substructures, which can tell us about the dynamical history, the properties of the cluster components, and perhaps fundamental physics.