1. School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA, UK
2. Department of Physics and Astronomy, University of the Western Cape, Private Bag X17, 7535 Bellville, Cape Town, South Africa
3. School of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
4. South African Astronomical Observatory, PO Box 9, Observatory, 7935 Cape Town, South Africa
5. Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh EH9 3HJ, UK
6. Astrophysics Group, Imperial College, Blackett Laboratory, Prince Consort Road, London SW7 2AZ, UK
7. INAF -- Osservatorio Astronomico di Padova, Vicolo dell Osservatorio 5, I-35122 Padova, Italy
8. School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
9. Department of Physical Science, The Open University, Milton Keynes MK7 6AA, UK
10. Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent, Belgium
11. Department of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854-8019, USA
12. Department of Physics and Astronomy, University of California, Irvine, CA 92697, USA
13. National Radio Astronomy Observatory, Green Bank, WV 24944, USA
14. Department of Astronomy, University of Maryland, College Park, MD 20742, USA
15. Astronomical Observatory Institute, Faculty of Physics, Adam Mickiewicz University, ul. Słoneczna 36, PL-60-286 Poznań, Poland
16. Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH, UK
17. Department of Astronomy, Cornell University, Ithaca, NY 14853, USA
18. Department of Physics and Astronomy, University of the Western Cape, Robert Sobukwe Road, 7535 Bellville, Cape Town, South Africa
19. INAF – Istituto di Radioastronomia, via Gobetti 101, I-40129 Bologna, Italy