Gaia EDR3 Proper Motions of Milky Way Dwarfs. II Velocities, Total Energy, and Angular Momentum

Here we show that precise Gaia EDR3 proper motions have provided robust estimates of 3D velocities, angular momentum and total energy for 40 Milky Way dwarfs. The results are statistically independent the mass profile. Dwarfs do not behave like long-lived satellites because their excessively large momenta, energies. Comparing them to other MW halo population, find many at first passage, $\le$ 2 Gyr ago, i.e., more recently than passage Sagittarius, $\sim$ 4-5 ago. We suggest this is in agreement with stellar populations all dwarfs, which a small fraction young stars cannot be excluded. also dwarf radial velocities contribute too little kinetic when compared satellite systems only regulated by gravity, some mechanism must work such as ram pressure. latter may preferentially reduced progenitors entered until they lost gas. It could explain why most dwarfs lie near pericenter. discover novel scale structure perpendicular disk, made 20% orbiting or counter Sagittarius dwarf.