REDSHIFTS OF CLUSTERS IN THE ALPHA-REGION

We present measurements of radial velocities of 46 galaxies in 11 clusters that are part of a recently identified very rich concentration of clusters. This concentration, lying northeast of the Centaurus cluster in an area of the sky dubbed by us "alpha region," is particularly interesting because of its large overdensity of relatively nearby clusters of galaxies and its angular proximity to the direction of the Local Group's peculiar motion with respect to the cosmic microwave background. The data presented here, together with new additional data from the literature, allow a better definition of a large supercluster, composed of 15 rich clusters, at an average comoving distance of 145h-1 Mpc. The core of this supercluster, defined by nine clusters (eight of which with richness greater than zero) distributed in an elongated structure, has an observed density that is greater than the one found in the Corona Borealis supercluster by more than a factor of 3.