1. Istituto Astrofisica Spaziale, Consiglio Nazionale delle Ricerche (CNR), Via Fosso del Cavaliere, 00133 Roma, Italy.
2. Department of Astronomy and Astrophysics, 525 Davey Lab, Pennsylvania State University, University Park, PA 16802, USA.
3. Harvard–Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA.
4. Department of Physics, Universita' Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy.
5. Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
6. National Radio Astronomy Observatory, 1003 Lopezville Road, Socorro, NM 87801, USA.
7. Istituto Tecnologie e Studio Radiazioni Extraterrestri/CNR, Via Gobetti 101, 40129 Bologna, Italy.
8. Department of Astrophysics, Columbia University, New York, NY 10027, USA.
9. Space Research Organization in the Netherlands, Sorbonnelaan 2, 3584 CA Utrecht, Netherlands.
10. University of California Space Science Laboratory, Berkeley, CA 94720, USA.
11. Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako-Shi, Saitama 351-0198, Japan.
12. University of Alabama, NASA/Marshall Space Flight Center, Huntsville, AL 35899, USA.
13. NASA/Goddard Space Flight Center, Code 661, Greenbelt, MD 20771, USA.
14. Institute of Space and Astronautical Science, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510, Japan.
15. Russian Academy of Sciences, Special Astrophysical Observatory Nizhnij Arkhyz, Zelenchukskaya, Karachaevo-Cherkesia 369167, Russia.
16. NASDA, National Space Development Agency of Japan, WTC Building 2-4-1, Hamamatsu-cho Minato-ku, Tokyo 105-60, Japan.