The abstract of Dr. Ran Li's talk is as follows:
In a cold dark matter (CDM) universe, dark matter haloes form hierarchically through accretion and merging. When a small halo merges to a larger one, it becomes a subhalo of the larger system. Numerical simulations show that the dark matter haloes are populated with numerous subhaloes. An promising way to investigate the satellite-subhalo relation is through stacking analysis of galaxy-galaxy lensing with large surveys. We make use of CFHT/Stripe82 Survey data to generate shear catalog and present the lensing measurement around satellite galaxies selected from cluster/group catalogs. We report the first measurement of subhalo mass in group sized galaxy with g-g lensing. With a cluster catalog, RedMapper, we also investigate the subhalo mass dependance on the halo-centric radius and stellar mass of the galaxies.