[1] DESY, D-15738 Zeuthen, Germany
[2] Clemson Univ, Kinard Lab Phys, Dept Phys & Astron, Clemson, SC 29634 USA
[3] Univ Pisa, Sez Pisa, I-56127 Pisa, Italy
[4] Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy
[5] Univ Paris Diderot, CEA Saclay, Serv Astrophys, CNRS,Lab AIM,CEA IRFU, F-91191 Gif Sur Yvette, France
[6] Ist Nazl Fis Nucl, Seze Trieste, I-34127 Trieste, Italy
[7] Univ Trieste, Dipartimento Fis, I-34127 Trieste, Italy
[8] Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy
[9] Univ Padua, Dipartimento Fis & Astron G Galilei, I-35131 Padua, Italy
[10] Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy
[11] Univ Bari, Dipartimento Fis M Merlin, I-70126 Bari, Italy
[12] Politecn Bari, I-70126 Bari, Italy
[13] Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy
[14] Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA
[15] Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA
[16] Ist Nazl Fis Nucl, Sez Torino, I-10125 Turin, Italy
[17] Univ Turin, Dipartimento Fis, I-10125 Turin, Italy
[18] Univ Padua, Dept Phys & Astron, Vicolo Osservatorio 3, I-35122 Padua, Italy
[19] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA
[20] Univ Montpellier, CNRS IN2P3, Lab Univ & Particules Montpellier, F-34095 Montpellier, France
[21] Ecole Polytech, IN2P3, CNRS, Lab Leprince Ringuet, F-91128 Palaiseau, France
[22] CRESST, Greenbelt, MD 20771 USA
[23] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA
[24] INAF Ist Astrofis Spaziale & Fis Cosm Milano, Via E Bassini 15, I-20133 Milan, Italy
[25] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA
[26] Italian Space Agcy, Via Politecn Snc, I-00133 Rome, Italy
[27] Naval Res Lab, Div Space Sci, Washington, DC 20375 USA
[28] Space Sci Data Ctr Agenzia Spaziale Italiana, Via Politecn Snc, I-00133 Rome, Italy
[29] Ist Nazl Fis Nucl, Sez Perugia, I-06123 Perugia, Italy
[30] INAF Ist Radioastron, I-40129 Bologna, Italy
[31] Univ Bologna, Dipartimento Astron, I-40127 Bologna, Italy
[32] Univ Telemat Pegaso, Piazza Trieste & Trento 48, I-80132 Naples, Italy
[33] Hiroshima Univ, Dept Phys Sci, Hiroshima 7398526, Japan
[34] Friedrich Alexander Univ Erlangen Nurnberg, Erlangen Ctr Astroparticle Phys, Erwin Rommel Str 1, D-91058 Erlangen, Germany
[35] Univ Maryland, Dept Astron, College Pk, MD 20742 USA
[36] Univ Orleans, CNRS, Lab Phys & Chim Environnem & Espace, F-45071 Orleans 02, France
[37] CNRS INSU, Observ Paris, Stn Radioastron Nancay, F-18330 Nancay, France
[38] George Washington Univ, Dept Phys, 725 21st St, Washington, DC 20052 USA
[39] Univ North Florida, Dept Phys, 1 UNF Dr, Jacksonville, FL 32224 USA
[40] Univ Iceland, Sci Inst, IS-107 Reykjavik, Iceland
[41] KTH Royal Inst Technol, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden
[42] Stockholm Univ, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden
[43] KTH Royal Inst Technol, Dept Phys, SE-10691 Stockholm, Sweden
[44] Oskar Klein Ctr Cosmoparticle Phys, SE-10691 Stockholm, Sweden
[45] Univ Bordeaux 1, IN2P3 CNRS, Ctr Etudes Nucl Bordeaux Gradignan, BP120, F-33175 Gradignan, France
[46] Inst Space Sci CSICIEEC, Campus UAB,Carrer Magrans S-N, E-08193 Barcelona, Spain
[47] Hiroshima Univ, Hiroshima Astrophys Sci Ctr, Hiroshima 7398526, Japan
[48] Ist Nazl Fis Nucl, Sez Roma Tor Vergata, I-00133 Rome, Italy
[49] Univ Denver, Dept Phys & Astron, Denver, CO 80208 USA
[50] Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany