1. National Radio Astronomy Observatory , 520 Edgemont Road, Charlottesville, VA 22903 , USA
2. South African Radio Astronomy Observatory (SARAO) , 2 Fir Street, Black River Park, Observatory, Cape Town 7925 , South Africa
3. Western Sydney University , Locked Bag 1797, Penrith South DC, NSW 2751 , Australia
4. Department of Astronomy, University of Virginia , Charlottesville, VA 22904 , USA
5. Lennard-Jones Laboratories, Keele University , Staffordshire ST5 5BG , UK
6. Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, The University of Manchester , Manchester M13 9PL , UK
7. INAF-Osservatorio Astrofisico di Catania , Via S. Sofia 78, I-95123 Catania , Italy
8. CSIRO Astronomy and Space Science , PO Box 76, Epping, NSW 1710 , Australia
9. Max-Planck-Institut für extraterrestrische Physik , Gießenbachstraße 1, D-85748 Garching , Germany
10. Institute for Astronomy, University of Edinburgh, Royal Observatory , Blackford Hill, Edinburgh EH9 3HJ , UK
11. Jodrell Bank Centre for Astrophysics, The University of Manchester , Oxford Road M13 9PL , UK
12. High Energy Physics, Cosmology & Astrophysics Theory (HEPCAT) Group, Department of Mathematics & Applied Mathematics, University of Cape Town , Cape Town 7700 , South Africa
13. SKA Observatory, Jodrell Bank , Lower Withington, Macclesfield, SK11 9FT , UK
14. Department of Physics and Astronomy, University of the Western Cape , Bellville, Cape Town 7535 , South Africa