High-resolution radio observations of Seyfert galaxies in the extended 12-mu m sample - II. The properties of compact radio components

We discuss the properties of compact nuclear radio components in Seyfert ga laxies from the extended 12-mum AGN sample of Rush et al. Our main results can be summarized as follows. Type 1 and type 2 Seyferts produce compact ra dio components which are indistinguishable in strength and aspect, indicati ng that their central engines are alike, as proposed by the unification mod el. Infrared IRAS fluxes are more closely correlated with low-resolution ra dio fluxes than high-resolution radio fluxes, suggesting that they are domi nated by kiloparsec-scale, extranuclear emission regions; extranuclear emis sion may be stronger in type 2 Seyferts. Early-type Seyfert galaxies tend t o have stronger nuclear radio emission than late-type Seyfert galaxies. V-s haped extended emission-line regions, indicative of 'ionization cones', are usually found in sources with large, collimated radio outflows. Hidden bro ad lines are most likely to be found in sources with powerful nuclear radio sources. Type 1 and type 2 Seyferts selected by their IRAS 12-mum flux den sities have well-matched properties.