1. Instituto de Astrofísica de Canarias (IAC), Vía Láctea s/n, La Laguna, E-38205 S/C de Tenerife, Spain
2. Departamento de Astrofísica, Universidad de La Laguna, La Laguna, E-38205 S/C de Tenerife, Spain
3. Instituto Argentino de Radioastronomía, (CCT – La Plata, CONICET – CICPBA), C.C.5, B1894 Villa Elisa, Buenos Aires, Argentina
4. Department of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, UK
5. Kapteyn Astronomical Institute, University of Groningen, PO Box 800, NL-9700 AV Groningen, the Netherlands
6. MIT Kavli Institute for Astrophysics and Space Research, 70 Vassar Street, Cambridge, MA 02139, USA
7. Eureka Scientific, Inc., 2452 Delmer Street, Oakland, CA 94602, USA
8. SRON, Netherlands Institute for Space Research, Sorbonnelaan 2, NL-3584 CA Utrecht, the Netherlands
9. Center for Astrophysics, Harvard University, 60 Garden Street, Cambridge, MA 02138, USA
10. Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque, B1900FWA La Plata, Argentina
11. X-ray Astrophysics Laboratory, Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
12. Department of Physics & Astronomy, Michigan State University, 567 Wilson Road, East Lansing, MI 48824, USA
13. Department of Astronomy, University of Maryland, College Park, MD 20742, USA
14. Department of Physics, University of Rome ‘Tor Vergata’, Via della Ricerca Scientifica 1, I-00133 Rome, Italy
15. Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK
16. Department of Physics, Villanova University, Villanova, PA 19085, USA
17. Anton Pannokoek Institute, University of Amsterdam, Science Park 904, NL-1098XH Amsterdam, the Netherlands