The Structure and Dynamics of Cold Dark Matter Halos

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We investigate the internal structure of cold dark matter halos using high resolution N-body simulations. As the mass and force resolution are increased, halo density profiles become steeper, asymptoting to a slope of -4/3 in the central regions and may not have converged to a unique result. At our highest resolution we have nearly 3 million particles within the virial radius, R₂₀₀, and force softening that is 0.2% R₂₀₀. This resolution has also allowed us to resolve a large part of the overmerging problem - we find over 1000 surviving dark halos orbiting within a single cluster potential. These data have given us unprecedented insights into the dynamics and structure of ``halos within halos'', allowing us for the first time, to compare the distribution of dark matter with observations of galaxies in clusters.