High Resolution Observations of the Radio Galaxy NGC5128 at 10.7 GHz

Maps of Centaurus A from Molonglo and Culgoora

“…The earlier low-resolution maps by Shain (1958) at 19.7 MHz, Sheridan (1958 at 85.5 MHz and Cooper et al (1965) at 406, 960, 1410 and 2650 MHz were able to trace emission over an angular area ~8° x4° centred on the peculiar elliptical galaxy NGC 5128. Later maps with an orderof-magnitude improvement in angular resolution, by Lockhart and Sheridan (1970) at 80 MHz, Slee and Sheridan (1975) at 160 MHz, Cameron (1969Cameron ( , 1971 at 408 MHz, Schwarz et al (1974) at 1410 MHz, Christiansen et al (1977) at 1415 MHz, Little (1961) at 3.3 GHz, Gardner and Whiteoak (1971) at 5 GHz and Price and Stull (1973) at 10.7 GHz, were not able to detect the emission from the low-surface-brightness outer lobes but did succeed in properly resolving the inner north-east and south-west lobes. Polarization studies by Bracewell et al (1962), Cooper et al (1965), Gardner and Whiteoak (1971), Price and Stull (1973) and Schwarz et al (1974) showed that ordered linear polarization was present over most of the large area occupied by the source; in the inner lobes the linear polarization reached levels of -6 0 % in some areas at 10.7 GHz.…”

“…Later maps with an orderof-magnitude improvement in angular resolution, by Lockhart and Sheridan (1970) at 80 MHz, Slee and Sheridan (1975) at 160 MHz, Cameron (1969Cameron ( , 1971 at 408 MHz, Schwarz et al (1974) at 1410 MHz, Christiansen et al (1977) at 1415 MHz, Little (1961) at 3.3 GHz, Gardner and Whiteoak (1971) at 5 GHz and Price and Stull (1973) at 10.7 GHz, were not able to detect the emission from the low-surface-brightness outer lobes but did succeed in properly resolving the inner north-east and south-west lobes. Polarization studies by Bracewell et al (1962), Cooper et al (1965), Gardner and Whiteoak (1971), Price and Stull (1973) and Schwarz et al (1974) showed that ordered linear polarization was present over most of the large area occupied by the source; in the inner lobes the linear polarization reached levels of -6 0 % in some areas at 10.7 GHz. A recent map from the VLA at 1420 MHz , with angular resolution 31" x 10" arc, shows the presence of three central sources, one of which is believed to be coincident with the nuclear engine at the centre of the optical galaxy, the other two sources being coincident with condensations in the X-ray jet (Feigelson et al 1981) which extends from the nucleus towards the inner north-east radio lobe.…”