Evidence for Ring Caustics in the Milky Way

The late infall of cold dark matter onto our galaxy produces streams and caustics in its halo. Sharp rises present in the rotation curve of the Milky Way are interpreted as due to the presence of caustic rings of dark matter in the galactic plane. Their locations are consistent at the 3% level with the predictions of the self-similar infall model for the ring radii. Also, a triangular feature in the IRAS map of the galactic plane is consistent with the imprint of a ring caustic upon the baryonic matter. These observations imply that the dark matter in our neighborhood is dominated by a single flow whose density and velocity vector are given. Typeset using REVTEX