On the Orbital Velocity of Isolated Galaxy Pairs: II Accurate MOND Predictions

Abstract

Examining a catalogue of isolated galaxy pairs, a preferred orbital intervelocity of ~150 km/s was recently reported. This discovery is difficult to reconcile with the expectations from Newtonian numerical simulations of cosmological structure formations. In a previous paper we have shown that a preferred intervelocity for galaxy pairs is expected in Modified Newtonian Dynamics (MOND). Here a detailed analysis of the MOND predictions is presented, showing that a remarkable agreement with the observations can be achieved for a mass to light ratio M/L~1 in solar units. This agrees with the expectations for a typical stellar population, without requiring non-baryonic dark matter for these systems.