The peculiar velocity field in the Perseus-Pisces supercluster

I describe the main results of a program to study peculiar motions of galaxies in the Perseus-Pisces supercluster. The data set consists of newly obtained CCD photometry and published 21 cm line widths for 320 spiral galaxies in the Perseus-Pisces region. The peculiar velocities of these objects are estimated using the Tully-Fisher relation, which has been calibrated with respect to an independent sample of cluster galaxies. Analysis of the Tully-Fisher data shows that the principal feature of the velocity field in the Perseus-Pisces region is a coherent streaming toward the Local Group. Nearly all the galaxies well in the foreground (cz ~ 8000 km s^-1^, are consistent with their being at rest. These streaming motions in Perseus-Pisces are similar in amplitude and direction to those of elliptical galaxies in the southern sky, which have large positive peculiar velocities to distances of at least 4000 km s^-1^. These have been modeled as arising from the pull of a "great attractor. " If, as seems probable, the flow traced by the Perseus-Pisces spirals is physically related to that of the elliptical galaxies, the coherence length for this streaming motion is of order 100h^-1^ Mpc. It is unlikely that coherent motion on this scale can arise entirely from the great attractor; rather, it may be due in part to low-amplitude density fluctuations on much larger scales.