Constraining the halo bispectrum in real and redshift space from perturbation theory and non-linear stochastic bias

KITAURA, FRANCISCO-SHU; GIL-MARÍN, HÉCTOR; SCOCCOLA, CLAUDIA GRACIELA; CHUANG, CHIA-HSUN; MÜLLER, VOLKER; YEPES, GUSTAVO; PRADA, FRANCISCO

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015 vol. 450 p. 1836 - 1845

0035-8711

We present a method to produce mock galaxy catalogues with efficientperturbation theory schemes, which match the number density, powerspectra and bispectra in real and in redshift space from N-bodysimulations. The essential contribution of this work is the way in whichwe constrain the bias parameters of the PATCHY-code. In addition toaiming at reproducing the two-point statistics, we seek the set of biasparameters, which constrain the univariate halo probability distributionfunction (PDF) encoding higher order correlation functions. Wedemonstrate that halo catalogues based on the same underlying darkmatter field with a fix halo number density, and accurately matching thepower spectrum (within 2 per cent) can lead to very different bispectradepending on the adopted halo bias model. A model ignoring the shape ofthe halo PDF can lead to deviations up to factors of 2. The cataloguesobtained additionally constraining the shape of the halo PDF cansignificantly lower the discrepancy in the three-point statistics,yielding closely unbiased bispectra both in real and in redshift space;which are in general compatible with those corresponding to an N-bodysimulation within 10 per cent (deviating at most up to 20 per cent). Ourcalculations show that the constant linear bias of ?2 for luminousred galaxy (LRG) like galaxies found in the power spectrum, mainly comesfrom sampling haloes in high-density peaks, choosing a high-densitythreshold rather than from a factor multiplying the dark matter densityfield. Our method contributes towards an efficient modelling of thehalo/galaxy distribution required to estimate uncertainties in theclustering measurements from galaxy redshift surveys. We have alsodemonstrated that it represents a powerful tool to test various biasmodels.