Modelling the redshift-space three-point correlation function in SDSS-III

Abstract

We present the measurements of the redshift-space three-point correlation function (3PCF) for z ~ 0.5 luminous red galaxies of the CMASS sample in the Sloan Digital Sky Survey- III Baryon Oscillation Spectroscopic Survey Data Release 11. The 3PCF measurements are interpreted within the halo occupation distribution framework using high-resolution N-body simulations, and the model successfully reproduces the 3PCF on scales larger than 1 h-1 Mpc. As with the case for the redshift-space two-point correlation functions,we find that the redshiftspace 3PCF measurements also favour the inclusion of galaxy velocity bias in the model. In particular, the central galaxy in a halo is on average in motion with respect to the core of the halo.We discuss the potential of the small-scale 3PCF to tighten the constraints on the relation between galaxies and dark matter haloes and on the phase-space distribution of galaxies.