[1] Univ Libre Bruxelles, Sci Fac CP230, B-1050 Brussels, Belgium
[2] Ohio State Univ, Ctr Cosmol & AstroParticle Phys, Dept Phys, Columbus, OH 43210 USA
[3] Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA
[4] Natl Nucl Res Univ MEPhI, Kashirskoe Shosse 31, Moscow 115409, Russia
[5] Univ Wisconsin, Wisconsin IceCube Particle Astrophys Ctr WIPAC, Madison, WI 53703 USA
[6] Univ Wisconsin, Dept Phys, Madison, WI 53703 USA
[7] Uppsala Univ, Dept Phys & Astron, SE-75237 Uppsala, Sweden
[8] Friedrich Alexander Univ Erlangen Nuremberg, Erlangen Ctr Astroparticle Phys ECAP, D-91058 Erlangen, Germany
[9] Vrije Univ Brussel, Astrophys Inst, Pl Laan 2, B-1050 Brussels, Belgium
[10] Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA
[11] Univ Chicago, Enrico Fermi Inst, Kavli Inst Cosmol Phys, Dept Phys, Chicago, IL 60637 USA
[12] Vrije Univ Brussel, Dienst ELEM, B-1050 Brussels, Belgium
[13] DESY, Platanenallee 6, D-15738 Zeuthen, Germany
[14] Whittier Coll, Whittier, CA 90602 USA
[15] Penn State Univ, Dept Phys, Dept Astron & Astrophys, University Pk, PA 16801 USA
[16] Univ Nebraska, Dept Phys & Astron, Lincoln, NE 68588 USA
[17] Radboud Univ Nijmegen, Dept Astrophys IMAPP, POB 9010, NL-6500 GL Nijmegen, Netherlands
[18] Univ Ghent, Dept Phys & Astron, B-9000 Ghent, Belgium
[19] Univ Delaware, Dept Phys & Astron, Newark, DE 19716 USA
[20] Univ Groningen, Kapteijn Inst, Groningen, Netherlands
[21] Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA
[22] Calif Polytech State Univ San Luis Obispo, Phys Dept, San Luis Obispo, CA 93407 USA