Near-infrared properties of moderate-redshift galaxy clusters.: II.: Halo occupation number, mass-to-light ratios, and Ωm

Using K- band imaging for 15 of the Canadian Network for Observational Cosmology ( CNOC1) clusters we examine the near- infrared properties of moderate- redshift ( 0.19 < z < 0.55) galaxy clusters. We find that the number of K- band selected cluster galaxies within R-500 ( the halo occupation number, HON) is well correlated with the cluster dynamical mass ( M-500) and X- ray temperature ( T-X); however, the intrinsic scatter in these scaling relations is 37% and 46%, respectively. Comparison with clusters in the local universe shows that the HON-M-500 relation does not evolve significantly between z = 0 and z similar to 0.3. This suggests that if dark matter halos are disrupted or undergo significant tidal stripping in high-density regions as seen in numerical simulations, the stellar mass within the halos is tightly bound, and not removed during the process. The total K- band cluster light ( L-200,L-K) and K-band-selected richness ( parameterized by B-gc,B- K) are also correlated with both the cluster T-X and M-200. The total ( intrinsic) scatter in the L-200,L-K-M-200 and B-gc,B-K- M-200 relations are 43% (31%) and 35% (18%), respectively, and indicates that for massive clusters both L-200,L-K and B-gc,B-K can predict M-200 with accuracy similar to that of T-X, L-X, or optical richness ( B-gc). Examination of the mass-to-light ratios of the clusters shows that similarly to local clusters, the K- band mass-to-light ratio is an increasing function of halo mass. Using the K-band mass-to-light ratios of the clusters, we apply the Oort technique and find Omega(m,0) = 0.22 +/- 0.02, which agrees well with recent combined concordance cosmology parameters, but, similarly to previous cluster studies, is on the low- density end of preferred values.