Fan-Beam Observations of Radio Sources at 408 and 1407 MHz

The Cambridge One-Mile Radio Telescope has been used in a one-dimensional synthesis to survey the radio sources in areas near δ = 50° totalling 0.15 steradians. The effective beamwidths between half-power points at 408 and 1407 MHz respectively were 100″ and 30″ arc in declination and 2°.5 and 50′ arc in right ascension. At 408 MHz some 200 sources having $$S_{408}\geqslant0.5\times10^{-26}\text{ W m}^{-2}\text{ Hz}^{-1}$$ were observed, and their declinations measured with an accuracy of ≃ 10″. At 1407 MHz sources within a smaller area of sky and having $$S_{1407}\geqslant0.3\times10^{-26}\text{ W m}^{-2}\text{ Hz}^{-1}$$ were observed. Among the sources are 82 from the 4C catalogue and the improved positional accuracy in declination has enabled a new search to be made for related optical objects. The results are being combined with those from the 5C surveys to derive the N(S) relationship for $$S_{408}\geqslant10^{-28}\text{ W m}^{-2}\text{ Hz}^{-1}$.$