1. Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507, Japan
2. Cosmic Dawn Center (DAWN), Jagtvej 128, DK2200 Copenhagen N, Denmark
3. Niels Bohr Institute, University of Copenhagen, Lyngbyvej 2, DK2100 Copenhagen Ø, Denmark
4. Institute for Cosmic Ray Research, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan
5. Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
6. Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
7. Academia Sinica Institute of Astronomy and Astrophysics, 11F of Astronomy-Mathematics Building, AS/NTU, No.1, Section 4, Roosevelt Road, Taipei 10617, Taiwan
8. Research Center for Space and Cosmic Evolution, Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan