Galaxy correlation functions in redshift space from large N-body simulations

Abstract

We computed galaxy‐galaxy correlation functions in redshift space with data generated from a set of large Cold Dark Matter N‐body (Ω=1) simulations. Galaxy halos were identified as local density maxima in the dark matter distribution and artificial magnitude limited galaxy catalogs were made. We simulated the observing process by choosing several galaxies as observing sites at 3 epochs from 3 simulations, and then by measuring the redshift, angular direction on the sky, and apparent magnitude of the galaxies. We then computed the 2‐point correlation function in redshift space, ξ(rp, π), as was done for the CfA (mB=14.5) redshift survey by Davis and Peebles (1983). The fluctuations from simulation‐to‐simulation in our small computational box (51.2 Mpc on a side) are too large to accurately distinguish the 3 epochs studied (b=2, 1.4, and 1) when computed as Davis and Peebles did. Furthermore, the simulated contours of constant ξ(rp, π) provide a poor match to the data—they are excessively elongated along th...