A correlation between ellipticity and core-strength in extended radio galaxies

We show that in the case extended radio sources a correlation exists between the fraction of the radio flux retained in the core component and the ellipticity of the underlying galaxy. The correlation is in the sense that stronger cores occur in flatter galaxies. It would seem that there exists a class of intrinsically rounder, redder, massive ellipticals with larger velocity dispersions and metallicities, that can form extended radio sources more efficiently. Thus the occurrence of a radio source appears to be related to the dynamical and chemical evolution of the Galaxy.