Production of Milky Way Structure by the Magellanic Clouds

Previous attempts at disturbing the Galactic disk by the Magellanic Clouds relied on direct tidal forcing. However, by allowing the halo to respond actively rather than remain a rigid contributor to the rotation curve, the Clouds may produce a wake in the halo which then distorts the disk. Recent work reported here suggests that the Magellanic Clouds use this mechanism to produce disk distortions sufficient to account for the location, position angle, and sign of the H I warp and the observed anomalies in stellar kinematics toward the Galactic anticenter and LSR motion. More generally, the observed response depends on the gravitational potential and therefore provides a diagnostic for the structure of the halo and its extent.