A dynamical interpretation of the radio jet in 3C 31

Abstract

The radio source 3C 31, which is positionally identified with the galaxy NGC 383, has recently been shown to contain two curved radio jets emanating from the galaxy's nucleus. In this paper, we demonstrate that the projected shape of these jets may be produced by a dynamical interaction between NGC 383 and its neighbour NGC 382. On the basis of this hypothesis, the orbital elements of the NGC383/NGC382 system are estimated and a mean V magnitude mass to light ratio of about 11 solar units is derived for the system. The inferred value for the jet velocity is approximately 500km/s. Some consequences for theoretical models of other extragalactic radio sources are briefly outlined.