Empirical properties of the mass discrepancy in groups and clusters of galaxies. IV. Double compact galaxies

For a sample of 24 double compact galaxies, line-of-sight velocities given by Sargent and by Chincarini and Rood, and magnitudes given by Zwicky, are used to estimate average dynamical mass, ratio of average dynamical mass to average absolute luminosity, and ratios of "best guess" virial mass to luminous mass, virial velocity dispersions V, and virial radii R. It is found that /M is correlated with V, but not with R. V is not significantly correlated with R. Subject heading: galaxies, clusters of