Hybrid maps of the milli-arcsecond structures of 3C 120, 3C 273, and 3C 345

Abstract

The milli-arcsec structures of 3C 120, 3C 273, and 3C 345 have been determined by 'hybrid' mapping at 5011 MHz and 10,651 MHz. Each of these sources is found to consist of a bright unresolved component with a resolved jetlike extension to one side. Spectral indices derived from the maps show that in each source there are high surface brightness features with flat or inverted spectra, and lower surface brightness features with steep spectra. In both 3C 273 and 3C 345, the position angle changes systematically between the most compact and the more extended structure.