HIGH DYNAMIC-RANGE VLA OBSERVATIONS OF 8 CORE-DOMINATED QUASARS

The Very Large Array has been used at 5 GHz to make high dynamic range observations of eight quasars with prominent cores. All exhibit on-sided jets, and all but one show evidence of diffuse halos. The luminosity of the extended emission by itself is sufficient for thee to be Fanaroff-Riley Class II radio sources. This interpretation is confirmed by the polarization of the extended structure: the inferred magnetic field is parallel to the jet axis in all cases, and in all but one instance turns to be nearly perpendicular to the jet at its outer end. We identify thee latter structures as classical terminal hotspots. Both the total intensity data and especially the polarization data strongly support the notion that these quasars are similar to the classical lobe-dominated quasars, but are oriented with jet axes close to the line of sight. If this is so, then the relatively high degrees of polarization observed in the terminal hotspots appear to require that the downstream fluid velocities in the hotspots are mildly relativistic, in the range 0.2≤υ/c≤0.8. This, in turn, implies that the jets are at least moderately relativistic over their entire length.