High resolution observations of Centaurus-A and Pictor-A at 160 MHz

Since early 1974 the radioheliograph operated by the Division of Radiophysics at Culgoora, N.S.W. has been used in a 160 MHz study of approximately 2000 catalogued sources in the declination range -460 to +350. In addition to measurements of flux densities and accurate positions at 160 MHz, brightness distributions are obtained for the sources that can be resolved by the 1'.9 x 1'.9 arc beams. A comparison of the brightness distributions at 160 MHz with those obtained from high-frequency measurements with similar angular resolution can yield valuable information about the energy distribution of the relativistic electrons, which are believed to be responsible for the radio emission from most non-thermal sources. Among the first objects to be examined were the strong southern radio galaxies Centaurus-A and Pictor-A. (author)