Multifrequency observations of 40 powerful extragalactic sources with the 5-km telescope

Abstract

Forty powerful extended extragalactic radio sources selected from the 3C catalogue have been mapped at 2.7 and 15.4 GHz with the Cambridge 5-km telescope, a few new observations at 5.0 GHz are also presented. The results are given as contour and vector maps and as tables of component parameters. The high resolution of the 15.4-GHz maps (0.67 arcsec in RA) has enabled hot-spots to be mapped in detail; multiple structure is shown to be very common. Observations of linear polarization at 2.7 GHz have been used to derive maps of percentage polarization and magnetic-field direction for 18 of the sources. The results have been combined with previously-published observations at 5.0 GHz in order to derive the spectral indices of hot-spots. For one source (3C 20), detailed distributions of spectral index, Faraday rotation and depolarization between 5.0 and 2.7 GHz have been derived.