FR II radio galaxies with z<0.3 -- II. Beaming and unification

Abstract

In a previous paper we presented measurements of the properties of jets and cores in a large sample of FRII radio galaxies with z < 0.3. Here we test, by means of Monte Carlo simulations, the consistency of those data with models in which the prominences of cores and jets are determined by relativistic beaming. We conclude that relativistic beaming is needed to explain the relationships between core and jet prominences, and that speeds between 0.5 and 0.7c on kpc scales provide the best fits to the data.