Discovery of a quasar with a wide angle radio tail in a distant cluster of galaxies.

Radio, optical, and X-ray observations of two extended radio sources separated by 99 arc sec (4C 08.66) are reported. Both sources are identified with quasars: z = 0.6227 for the northern source, and z = 0.2282 for the southern. A faint cluster of galaxies is found near the northern source, and the radio structure of this source is interpreted as providing evidence for relative motion between the quasar and the cluster gas, just as Hintzen et al. (1981) interpreted their quasar-cluster association, 3C 275.1. Physical parameters for the core and the extended emission of the northern quasar are estimated. Limits on the magnetic field strength and angular diameter are derived from the radio spectrum of the core and the magnetic field direction in the jet is found from polarization measurements. The morphology of the X-ray source is consistent with inverse-Compton emission from relic radio lobes, but an origin from the quasar itself or cluster gas cannot be ruled out.