Observations of Cygnus a at 15 GHz with the 5-km Radio Telescope

Abstract

The compact ‘ head ’ regions in the components of Cygnus A have been mapped with the 5-km telescope at 15·4 GHz, the resolution being |${0}^{\prime{}\prime}\,\cdot65$| arc in right ascension and |${1}^{\prime{}\prime}\,\cdot0$| arc in declination. The maps reveal, as had been inferred from preliminary 15 GHz observations with the 5-km telescope, that the ‘ head ’ in the Sf component has a sharply truncated leading edge. A comparison of the present data with those previously obtained at 5 GHz those of the lower brightness ‘ tails ’. Improved estimates have been obtained of the physical conditions within the various regions of the source.