Astrophysical signatures of caustic ring of dark matter*

The caustic ring model is a proposal for full phase space distribution of cold dark matter in the galactic halo which predicts the existence of ring caustics in the galactic plane. Under self-similarity, the radius of a caustic ring increases on cosmological time scales. We have studied the effects of a caustic ring on the stars and interstellar gas as the caustic sweeps through the stellar disk. We have found that a stellar orbit is strongly perturbed by the gravitational field of a nearby caustic. Simulating the dynamics of half a million stars under the influence of each caustic ring, we have predicted the relative over-densities of the stars to be approximately 120, 45, 30 and 15% near the 2nd, 3rd, 4th and 5th caustic rings. We have also determined the density profile of interstellar gas near each caustic ring.