Confirmation of a large-scale, large-amplitude flow in the direction of the great attractor

Abstract

New spectroscopy and photometry have been obtained for 136 elliptical and S0 galaxies in the direction of the large-scale streaming flow described by Dressler et al. and Lynden-Bell et al. These data are used with the Dn-sigma relation to predict distances for these galaxies, and, by comparison with their observed radial velocities, to predict their peculiar motions relative to a smooth Hubble flow. In excellent agreement with the earlier work, a gradually rising, coherent flow is found in the direction of the Hydra-Centaurus supercluster out to a distance of about 3000 km/s with an average flow velocity of about 1000 km/s with respect to the frame defined by the cosmic background radiation. The peculiar motions are then seen to decrease to near zero by a distance of about 4000 km/s. This is in general agreement with the model proposed by Lynden-Bell et al., which ascribes the flow to the gravitational pull of a 'great attractor'. 25 refs.