COLORS, AGES, AND METALLICITIES OF GALAXIES IN SIX NEARBY GALAXY CLUSTERS

We present an optical-infrared photometric study of galaxies in six nearby clusters of galaxies at z=0.041 similar to 0.098 (A1436, A1773, A1809, A2048, A2142, and A2152). Using BVI photometry obtained at the Bohyunsan Optical Astronomical Observatory and JHK(S) photometry extracted from the 2-Micron All-Sky Survey catalog, we investigate the colors of galaxies in the clusters. Using the (B - V) versus (I - K-S) color-color diagrams in comparison with the simple stellar population model, we estimate the ages and metallicities of bright early-type member galaxies. Early-type galaxies in each cluster show the color-magnitude relation. Ages and metallicities of early-type members show little dependence on their velocity dispersions. Mean ages of early-types in the clusters range from 3 Gyr to 20 Gyr, showing a large dispersion, and mean metallicities range from Z = 0.03 to 0.05 above the solar value, showing a negligible dispersion.