A Re-Examination of the Origins of the Peculiar Velocity Field Within the Local Supercluster

The recent re-evaulation of the peculiar velocity field outside the Local Supercluster (Dekel et al. 1999) has permitted a re-examination of the origins of the peculiar velocity field within the Local Supercluster using the Mark III Catalog of Galaxy Peculiar Velocities. It is shown that the large-scale coherent pattern of peculiar velocities within the LSC are well-fit by a combination of the Outside-Region-(generated)-Motions (O-R-M) from the Potent model with a Virgocentric infall pattern that produces 220 km s −1 of Virgocentric infall at the Local Group towards the Virgo cluster moving at 88 km s −1 towards the Local Group. The part of the LG CMB motion this model cannot fit is that perpendicular to the Supergalactic plane. On what size scale this SGZ motion of the Local Group is shared by neighboring galaxies cannot be determined from the present data set, but can be found if we can accurately measure galaxy distances close to the Galactic plane. 1. The Four Issues to be Addressed