Radio jets in classical double radio sources with strong cores.

Fifteen luminous radio galaxies and quasars with strong cores were observed with high dynamic range using the VLA at 6 cm. These observations were intended to determine if classical double (class II) sources have a significantly lower probability of jet emission, as had been suggested from lower contrast maps. About 50 percent of the sample contains jets, significantly higher than that seen for doubles with weaker cores. The properties of these jets are different from those of lower luminosity (class I) sources; these jets tend to be clumpy, they are all one-sided, and their integrated 6 cm powers are 100-1000 times larger than jets in class I sources. However, the jet flow efficiencies do not significantly differ from class I sources. A comparison of the internal jet pressures with the external pressures (estimated from X-ray data) indicates that thermal confinement can just be made to work. The limits on the ratios of jet to counterjet fluxes are not inconsistent with relativistic beaming. However, the distribution of core powers and the ratio of core to hot spot distances on opposite sides of the cores are not consistent with relativistic beaming.