Space Velocities of Dwarf Galaxies in the Local Group from HST Proper Motions

The Local Group has been the benchmark for testing and calibrating many aspects of cosmological and galaxy formation theories. Thanks to the advancements in both observational and theoretical areas, our understanding about the galaxy formation and evolution in the Local Group has greatly improved in the last decade. Nonetheless, many fundamental parameters (e.g., total mass of the Local Group) still remain poorly constrained due to the limited information on the transverse motions of galaxies in the Local Group. Accurate proper motion measurements are required to resolve this issue, and the HSTPROMO (High-resolution Space Telescope Proper Motion) collaboration has been in the forefront of providing them for many galaxies, star clusters, and individual stars in the Local Group. In this contribution, I will present results from our recent HST study to measure proper motions of dwarf galaxies in the Local Group, and discuss implications.