Large peculiar velocities in the Hydra-Centaurus supercluster

Distances from the infrared Tully-Fisher relation have been obtained with the Parkes radio telescope for six clusters of galaxies in the Hydra-Centaurus supercluster. Three of these clusters show significant positive peculiar velocities of order 500 km/s in a comoving reference frame in which the observer is at rest with respect to the cosmic microwave background radiation. The net peculiar velocity of the sample suggests that Hydra-Centaurus tends to share the motion of the Local Group in this reference frame. The data also fit a model in which two mass concentrations, one at Virgo and one just beyond the centroid of the Parkes sample, perturb the Hubble flow. 54 references.