1. Max-Planck-Institut für Radioastronomie , Auf dem Hügel 69, D-53121 Bonn , Germany
2. Max Planck Institute for Gravitational Physics (Albert Einstein Institute) , D-30167 Hannover , Germany
3. Leibniz Universität Hannover , D-30167 Hannover , Germany
4. SKA Observatory , Jodrell Bank, Lower Withington, Macclesfield SK11 9FT , UK
5. Center for Astrophysics | Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138 , USA
6. National Radio Astronomy Observatory , PO Box O, 1003 Lopezville Road, Socorro, NM 87801 , USA
7. William H. Miller III Department of Physics and Astronomy, Johns Hopkins University , Baltimore, MD 21218 , USA
8. Landessternwarte, Universität Heidelberg , Königstuhl 12, D-69117 Heidelberg , Germany
9. Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, The University of Manchester , Manchester M13 9PL , UK
10. Research School of Astronomy and Astrophysics, Australian National University , Canberra, ACT 2611 , Australia
11. South African Radio Astronomy Observatory , 2 Fir Street, Black River Park, Observatory 7925 , South Africa
12. INAF – Osservatorio Astronomico di Cagliari , Via della Scienza 5, I-09047 Selargius (CA) , Italy
13. Department of Physics and Astronomy, University of British Columbia , 6224 Agricultural Road, Vancouver, BC V6T 1Z1 , Canada