[1] Univ Hamburg, Inst Expt Phys, D-22761 Hamburg, Germany
[2] Max Planck Inst Kernphys, D-69029 Heidelberg, Germany
[3] Yerevan Phys Inst, Yerevan 375036, Armenia
[4] UPS, CNRS, Ctr Etud Spatiale Rayonnements, F-31029 Toulouse 4, France
[5] Humboldt Univ, Inst Phys, D-12489 Berlin, Germany
[6] Observ Paris, CNRS, UMR 8102, Lab Univers & Theories,Sect Meudon, F-92195 Meudon, France
[7] Univ Durham, Dept Phys, Durham DH1 3LE, England
[8] North West Univ, Unit Space Phys, ZA-2520 Potchefstroom, South Africa
[9] Ecole Polytech, CNRS, IN2P3, Lab Leprince Ringuet, F-91128 Palaiseau, France
[10] CNRS, IN2P3, Lab Annecy Le Vieux Phys Particules, F-74941 Annecy Le Vieux, France
[11] Univ Paris 07, CNRS, CEA,UMR 7164, Observ Paris, F-75025 Paris 13, France
[12] Dublin Inst Adv Studies, Dublin 2, Ireland
[13] Heidelberg Univ, Landessternwarte Konigstuhl, D-69117 Heidelberg, Germany
[14] Univ Montpellier 2, CNRS, IN2P3, Lab Phys Theor & Astroparticules, F-34095 Montpellier 5, France
[15] CE Saclay, CEA, DSM, DAPNIA, F-91191 Gif Sur Yvette, France
[16] Univ Grenoble 1, CNRS, Inst Natl Sci Univers, Lab Astrophys Grenoble, F-38041 Grenoble 9, France
[17] Univ Tubingen, Inst Astron & Astrophys, D-72076 Tubingen, Germany
[18] Univ Paris 06, CNRS, IN2P3, Phys Theor & Hautes Energies Lab, F-75252 Paris 5, France
[19] Univ Paris 07, F-75252 Paris 5, France
[20] Charles Univ Prague, Inst Nucl & Particle Phys, CR-18000 Prague 8, Czech Republic
[21] Ruhr Univ Bochum, Lehrstuhl Weltraum & Astrophys 4, Inst Theoret Phys, D-44780 Bochum, Germany
[22] Univ Namibia, Windhoek, Namibia
[23] Univ Erlangen Nurnberg, Inst Phys, D-91058 Erlangen, Germany