Bispectrum and Nonlinear Biasing of Galaxies: Perturbation Analysis, Numerical Simulation, and SDSS Galaxy Clustering

摘要

Weconsidernonlinearbiasingmodelsofgalaxieswithparticularattentiontoacorrelationbetweenthelinearandquadraticbiasingcoefficients,$$b_1$$and$$b_2$$.Wefirstderiveperturbativeexpressionsfor$$b_1$$and$$b_2$$inhaloandpeakbiasingmodels.Wethendiscussourcomputationsofthepowerspectraandbispectraofdarkmatterparticlesandhalosusing$$N$$-bodysimulationdataandofvolume-limitedsubsamplesofSloanDigitalSkySurvey(SDSS)galaxies,anddeterminetheir$$b_1$$and$$b_2$$.Wefindthatthevaluesofthosecoefficientsatlinearregimes($$k0.2$$$$h$$Mpc$$^{-1}$$)arefairlyinsensitivetotheredshift-spacedistortionandthesurveyvolumeshape.Theresultingnormalizedamplitudesofthebispectra,$$Q$$,forequilateraltrianglesareinsensitivetothevaluesof$$b_1$$,implyingthat$$b_2$$indeedcorrelateswith$$b_1$$.ThepresentresultsexplainthepreviousfindingofKayoetal.(2004,PASJ,56,415)forthehierarchicalrelationofthree-pointcorrelationfunctionsofSDSSgalaxies.Whiletherelationsbetween$$b_1$$and$$b_2$$arequantitativelydifferentforspecificbiasingmodels,theirapproximatelysimilarcorrelationsindicateafairlygenericoutcomeofthebiasingduetothegravityinprimordialGaussiandensityfields.