The Great Attractor ? A Cosmic String?

Abstract

A brief review is made of the observational work on large-scale streaming motions in the Local Universe. There is considerable controversy as to whether the Great Attractor model of these streaming motions is correct. Preliminary results are presented of a southern sky survey of spiral galaxies to measure their peculiar velocities using the Tully-Fisher relationship. The region of strong peculiar motions has an elongated shape some 80° in angular extent centred roughly on the Great Attractor enclosing the brightest parts of the supergalactic plane. The peculiar velocities reverse in sign at a distance of 4000 km S-i which is conclusive evidence that such a dominant attracting region exists at that distance. However, there is little evidence of galaxies associated with this attracting mass and most galaxies appear to be participating in the streaming motions. The conclusion is that the attractor is largely invisible. It is proposed that a large moving loop of cosmic string is responsible for the peculiar velocities of the galaxies.