| Abstract | Recently published IR photometry of early-type galaxies in Virgo and Coma is used to study the IR color-magnitude (C-M) relations in these clusters. It is found that the relative distance moduli between Virgo and Coma derived from the u-V, u-K, and V-K colors are delta m = 3.5 + or - 0.2, 3.0 + or - 0.2, and 2.6 + or - 0.3 mag, respectively. The differences in these values provide evidence that the C-M effect does not have a universal form. It is suggested that many Coma galaxies lost their gas content before the formation of a cool, stellar component found in Virgo (and galaxies not in rich clusters) could occur. This cool component might consist either of very metal-rich stars or very red intermediate-age giants. |
