Structure of Dark Matter Halos from Hierarchical Clustering

University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan

Abstract


We investigated the structure of the dark matter halo formed in the cold dark matter scenarios by N-body simulations with parallel treecode on GRAPE cluster systems (Fukushige et al. 2004, ApJ, 606, 625). We simulated 8 halos with the mass of 4.4 × 10¹⁴ M_๏ to 1.6 × 10¹⁵ M_๏ in the SCDM and LCDM model using up to 30 million particles. With the resolution of our simulations, the density profile is reliable down to 0.2 percent of the virial radius. Our results show that the slope of inner cusp within 1 percent virial radius is shallower than -1.5, and the radius where the shallowing starts exhibits run-to-run variation.