The Cluster Mass Function inCOBE‐ and Cluster‐normalized Cold Dark Matter Simulations

Abstract

We introduce a set of four new publicly available N-body simulations, the most recent additions to the ever expanding Texas P3M Database. Our models probe the less studied parameter space region of moderate volume (100 h-1 Mpc box) combined with fine mass resolution (∝1012 M☉, roughly comparable to an L* galaxy; 1403 particles with Mparticle = 1011Ω0 h-1 M☉), making these simulations especially suitable for study of major large-scale structure features, such as voids and walls, and for comparison with the largest three-dimensional redshift surveys currently available (CfA2, SSRS2, IRAS PSCz). We match the above quartet with a set of smaller (40 h-1 Mpc), higher resolution simulations (Mparticle = 1010Ω0 h-1 M☉), to verify the reliability of the derived dark matter halo mass function at the small mass end. Our cosmological models (LCDM, TOCDM, OCDM, TCDM) are all COBE-normalized and, when possible (LCDM and TOCDM), also cluster-normalized, based on the X-ray cluster M-T relation. The COBE- and cluster-normalized LCDM model reiterates the attractiveness of this currently favored model, which does not require the introduction of tilt in order to snugly fit the ever narrowing constraints imposed by observational estimates of other cosmological parameters.