Acknowledgements

AJH thanks fellow members of the Astrophysics Dept at the University of Sydney for sharing their experience in many useful discussions which assisted in the development of techniques described here, and especially Taisheng Ye for reducing the Molonglo data prior to the commencement of this study and for determining the rms noise values.

We thank the anonymous referee for helpful comments.

This research has used data from the COSMOS/UKST Southern Sky Catalogue provided by the Anglo-Australian Observatory and has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, Caltech, under contract with the US National Aeronautics and Space Administration. The Molonglo Observatory Synthesis Telescope is funded by the Australian Research Council and the University of Sydney. AJH acknowledges the support of a Sydney University Postgraduate Scholarship from the School of Physics.

© Copyright Astronomical Society of Australia 1997