Dynamics of some remote superclusters

Redshifts of clusters of galaxies have been obtained in four regions of the sky selected as suspected rich superclusters at intermediate redshift (0.1 < z < 0.3). Measurements to date have detected the existence of several superclusters with dimensions up to 50 h-1 Mpc, irregular shapes, and containing as many as seven rich clusters in the richest supercluster. The velocity dispersions suggest some slowing of the Hubble flow internal to the superclusters. However, the inferred mass densities are low enough to prefer an open universe if the mass-to-luminosity ratios within the best-studied superclusters are comparable to the universal ratio. (Auth.)