[1] INAF IASF Roma, I-00133 Rome, Italy
[2] Univ Roma Tor Vergata, Dip Fis, I-00133 Rome, Italy
[3] INAF IASF Palermo, I-90146 Palermo, Italy
[4] NASA, Goddard Space Flight Ctr, CRESST, Greenbelt, MD 20771 USA
[5] Univ Maryland Baltimore Cty, Joint Ctr Astrophys, Baltimore, MD 21250 USA
[6] INAF OATS, I-34143 Trieste, Italy
[7] SNS, I-56126 Pisa, Italy
[8] OATO INAF, I-10025 Pino Torinese, To, Italy
[9] Hiroshima Univ, Dept Phys Sci, Higashihiroshima 7398526, Japan
[10] Hiroshima Univ, Hiroshima Astrophys Sci Ctr, Higashihiroshima 7398526, Japan
[11] INFN Roma Tor Vergata, I-00133 Rome, Italy
[12] OAB INAF, I-20121 Milan, Italy
[13] INAF IASF Milano, I-20133 Milan, Italy
[14] Univ Space Res Assoc, Columbia, MD 21044 USA
[15] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA
[16] Univ Coll London, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England
[17] Univ Colorado, Denver, CO 80202 USA
[18] Aalto Univ, Metsahovi Radio Observ, FIN-02540 Kylmala, Finland
[19] Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA
[20] Natl Cent Univ, Inst Astron, Chungli 32054, Taiwan
[21] St Petersburg State Univ, Astron Inst, St Petersburg, Russia
[22] Pulkovo Observ, St Petersburg, Russia
[23] Isaac Newton Inst Chile, St Petersburg Branch, St Petersburg, Russia
[24] Osserv Astrofis Catania, INAF, Catania, Italy
[25] Univ Turku, Dept Phys & Astron, Tuorla Observ, FI-21500 Piikkio, Finland
[26] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA
[27] INAF IASF Bologna, I-40129 Bologna, Italy
[28] CIFS Torino, I-10133 Turin, Italy
[29] Univ Trieste, Dipartmento Fis, I-34127 Trieste, Italy
[30] INFN Trieste, I-34127 Trieste, Italy
[31] ENEA Frascati, I-00044 Rome, Italy
[32] Univ Turin, Dip Fis, Turin, Italy
[33] ENEA Bologna, I-40129 Bologna, Italy
[34] INFN Roma La Sapienza, I-00185 Rome, Italy
[35] INAF OAC, I-09012 Capoterra, Italy
[36] Univ Insubria, Dip Fis, I-22100 Como, Italy
[37] ASI Sci Data Ctr, I-00044 Rome, Italy
[38] Agenzia Spaziale Italiana, I-00198 Rome, Italy