1. IRAP, Université de Toulouse, CNRS, CNES, UPS, 9 av. du colonel Roche, F-31038, Toulouse, France
2. Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa
3. SKA South Africa, 3rd Floor, The Park, Park Road, Pinelands 7405, South Africa
4. Astrophysics, Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH, UK
5. GEPI, Observatoire de Paris, CNRS, Université Paris Diderot, 5 place Jules Janssen, F-92190 Meudon, France
6. Department of Physics & Electronics, Rhodes University, PO Box 94, Grahamstown 6140, South Africa
7. Australia Telescope National Facility, CSIRO, PO Box 76, Epping, New south Wales 1710, Australia
8. ASTRON, the Netherlands Institute for Radio Astronomy, Postbus 2, NL-7990 AA Dwingeloo, The Netherlands