RECONSTRUCTING POSITIONS AND PECULIAR VELOCITIES OF GALAXY CLUSTERS WITHIN 20000 Km/sec

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Starting from the observed redshift distribution of a volume limited Abell/ACO cluster sample we use a 2-step procedure to recover their distances and peculiar velocities (assuming linear theory and linear biasing). The resulting 3D dipole is found to be 23% less than the corresponding z-space one which leads to a value of β≈ 0.21 consistent with an Ω∘=1 Universe. The cluster velocity field is dominated by a large-scale streaming motion towards the Shapley concentration and the resulting bulk velocity agrees extremely well with that deduced by POTENT, on smaller scales. Our results are in strong disagreement with those of Lauer & Postman.