7.960 MC/S Observations of Radio Sources in the Sydney Catalogue

During March and September 1960, observations were made with the Caltech interferometer of 739 sources listed in the two catalogues of Mills, Slee and Hill^1,^2. The primary purpose of the investigation was to provide this observatory with a 960 Mc/s "finding list" for future measurements of source sizes and precise positions. The area covered in these observations was: 0: -50° to -20° a: 17 to 5 hours o: -20° to +10° a: O to 24 hours. In general, the observations were restricted to sources in the MSH catalogues whose flux density at 86 Mc/s was greater than 15 x l0^(-26) watts m^-2 (c/s)^-l. All sources down to this level were examined with the exception of those in the region 18h to 24h, between o^o and -10° . Most sources were observed near transit for at least four or five minutes at the position given in the Sydney catalogues. This allowed us to observe one 10-degree declination zone each night. The flux density of each source was measured relative to the standard source Hydra A ( 09-14), which was observed each night when possible. When Hydra A was not available, 22-11 was used as a secondary calibrator. All observations were made at night to avoid effects of solar radiation.