Large-aperture BVRJK photometry of rich Abell clusters - Constraints on dark matter

Abstract

This paper presents results of large (arcmin), single-aperture JK photometry and CCD BVR photometry on and near the centers of distant (Z between values of 0.14 and 0.20), rich Abell clusters. The colors of the integrated light of the cores of these clusters are consistent with those of nearby E and S0 galaxies. The absence of anomalous infrared emission provides the strongest constraint to date on the possible stellar make-up of the dark matter in clusters of galaxies, requiring K band (2.2 microns) mass-to-light ratios of the dark matter of (M/L)K not less than 400h. Indeed, no more than 5/h percent of the dark mass can be made of objects with mass greater than 0.1 solar mass. Although these results do not require a contribution of nonbaryonic matter, they provide some constraints on the mass function for baryonic objects which might compose the dark matter. These conclusions do not depend on the detailed distribution of the dark matter in the clusters. 35 refs.