Mass Selection Bias in Galaxy Cluster Peculiar Velocities from the Kinetic Sunyaev-Zel'dovich Effect

Abstract

Upcoming surveys for galaxy clusters using the Sunyaev-Zel'dovich effect are potentially sensitive enough to create a peculiar velocity catalog. The statistics of these peculiar velocities are sensitive to cosmological parameters. We develop a method to explore parameter space using N-body simulations in order to quantify dark matter halo velocity statistics which will be useful for cluster peculiar velocity observations. We show that mass selection bias from a kinetic Sunyaev-Zel'dovich velocity catalog forecasts rms peculiar velocities with a much more complicated Omega_m dependency than suggested by linear theory. In addition, we show that both two-point functions for velocities disagree with linear theory predictions out to separations of approx. 40 Mpc/h. A pedagogical appendix is included developing linear theory notation with respect to the two-point peculiar velocity functions.