High-dynamic-range VLA observations of the quasar 3C 345

The VLA has been used to make high-dynamic-range 5-GHz maps of the total intensity and linear polarization of the core-dominated, superluminal quasar 3C 345 at a variety of resolutions. In spite of the large degree of bending that has been observed on the milliarcsecond scale, it is found that the arcsecond jet is very straight along position angle 319 deg for the first 2 arcsec, and then has two further knots oriented along position angle 327 deg. High-resolution polarization maps of the jet show that the inferred magnetic field is offset about 30 deg from the jet axis along the first 2 arcsec. There also appears to be a faint counterjet oriented at position angle 55 deg, nearly opposite the direction of ejection of a milliarcsecond component. The jet/counterjet luminosity ratio suggests a jet speed of about 0.56c. The source is surrounded by a diffuse, asymmetric halo which extends about 15 arcsec to the south, away from both the direction of the jet and the possible counterjet. The halo luminosity, arcsecond-scale jet, hotspots, and polarization structure of 3C 345 confirm that it is an ordinary double-lobed radio quasar seen nearly end-on. 24 refs