The Molonglo Deep Sky Survey of Radio Sources. III. Source Counts

Abstract

Number-flux density counts of radio sources are given for the first two deep surveys made with the Molonglo Mills Cross at 408 MHz, extending to lower limits of 84 and 88 mJy. Practical techniques are developed for the calculation of corrections to the counts when confusion errors are significant. The resulting corrections due to noise, confusion and other effects are given. Counts are also given for the MC2 and MC3 catalogues in the range 2-10 Jy to reduce the statistical uncertainties there. Results are shown on a composite plot, using relevant Molonglo surveys and an all-sky catalogue of strong sources. The existence of a convergence in the number of weak sources is confirmed.