Cluster-Galaxy Correlation Function in COBE Normalized CDM Models

MERCHÁN, MANUEL E; ABADI, M.; DIEGO GARCIA LAMBAS; CARLOS A. VALOTTO

Workshop; 12th Potsdam Cosmology Workshop; 1997

We analyze the galaxy-galaxy and cluster-galaxy two-point correlation functions, xigg and xicg, in open (Omega0=0.4, OmegaLambda=0, sigma_8=0.75, h100=0.65$), and flat (Omega0=0.3, OmegaLambda=0.7, sigma_8=1.05, h100=0.65$) CDM models which both reproduce the observed abundances of rich clusters of galaxies. We estimate xicg for a sample taken from the APM cluster survey finding a power-law fit xicg=({r / r0})gamma with r0=10.0 +/- 0.7 h^{-1} Mpc and gamma ~= -2.1. For the open and flat-antibiased CDM models explored we find the corresponding cluster-galaxy correlation lengths 6.5 +/- 0.7 h^{-1} Mpc and 7.2 +/- 0.5 h^{-1} Mpc respectively, significantly lower than the observed value. Our results indicate that COBE-normalized CDM models are not able to reproduce the spatial cross-correlation of clusters and galaxies.