Jodrell Bank MTRLI observations of nine core-dominated sources at 408 MHz

The Jodrell Bank MTRLI has been used to map nine flat-spectrum core-dominated radio sources at 408 MHz. Most of the sources consist of a compact core with a flat spectrum and an extended 'jet' component with a steeper spectrum. Evidence is presented that in several of the sources there is, in addition to the core and the jet which are visible on the maps, a halo component of relatively low brightness and very steep spectrum. The observations are interpreted within the framework of relativistic beam models and it is concluded that core-dominated quasars are most likely to be classical double radio quasars seen end-on. The diffuse halo is identified with the superposed outer lobes, and the jet with one of the relativistic beams transporting energy to the lobes.