1. Departamento de Física de la Tierra y Astrofísica , IPARCOS, Universidad Complutense de Madrid, E-28040 Madrid, Spain
2. Instituto de Astrofísica de Canarias , Vía Láctea S/N, E-38205 La Laguna, Tenerife, Spain
3. Departamento de Astrofísica , Universidad de La Laguna, E-38206 La Laguna, Tenerife, Spain
4. Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester , Alan Turing Building, Oxford Road, Manchester M13 9PL, UK
5. Istituto di Radioastronomia – INAF , Via P. Gobetti 101, I-40129 Bologna, Italy
6. School of Physics and Astronomy, University of Southampton , Southampton SO17 1BJ, UK
7. Astrophysics Group, Cavendish Laboratory , 19 J. J. Thomson Avenue, Cambridge CB3 0HE, UK
8. Department of Space, Earth and Environment, Chalmers University of Technology , SE-412 96 Göteborg, Sweden
9. Instituto de Astrofísica de Andalucía , IAA-CSIC, Glorieta de la Astronomía s/n, E-18008 Granada, Spain
10. Jeremiah Horrocks Institute, University of Central Lancashire , Preston, Lancashire PR1 2HE, UK
11. Max-Planck-Institut für Radioastronomie , Auf dem Hügel 69, D-53121 Bonn, Germany
12. Technical University of Kenya , P.O. box 52428-00200 Nairobi, Kenya
13. Inter-University Centre for Astronomy and Astrophysics (IUCAA) , P.O., Post Bag 4, Ganeshkhind, Pune 411 007, India
14. Center for Astro, Particle and Planetary Physics, New York University Abu Dhabi , PO Box 129188 Abu Dhabi, UAE
15. School of Physics and Astronomy, University of Birmingham , Birmingham B15 2TT, UK