Statistical masses of Abell clusters

The analysis of a homogeneous sample of 108 Abell clusters has led to an average peculiar velocity for the center of mass motion of these clusters of 610±750 km s^–1. From this result, an upper limit for the average mass of the Abell clusters of (1.6±2.4)×10¹⁵ M was obtained under the assumption that the peculiar motion is due to the excess of neighbours with respect to an uniform background. A lower limit of (2.42.9) x 10¹⁴ h ^-10.4 M was derived if one assumes that the peculiar velocity results from the mutual acceleration with the nearest neighbour.