Measurement of the Anisotropy of Cosmic-ray Arrival Directions with IceCube

• Published in: The Astrophysical Journal
• Main Authors: Abbasi, R., Abdou, Y., Abu-Zayyad, T., Adams, J., Aguilar, J. A., Ahlers, M., Andeen, K., Auffenberg, J., Bai, X., Baker, Mark D., Barwick, S. W., Bay, R., Bazo Alba, J. L., Beattie, K., Beatty, J. J., Bechet, S., Becker, J. K., Becker, K.-H., Benabderrahmane, M. L., Benzvi, S., Berdermann, J., Berghaus, P., Berley, D., Bernardini, E., Bertrand, D., Besson, D. Z., Bissok, M., Blaufuss, E., Boersma, D. J., Bohm, C., Böser, S., Botner, O., Bradley, L., Braun, J., Buitink, S., Carson, M., Chirkin, D., Christy, B., Clem, J., Clevermann, F., Cohen, S., Colnard, C., Cowen, D. F., d'Agostino, M. V., Danninger, M., Davis, J. C., de Clercq, C., Demirörs, L., Depaepe, O., Descamps, F., Desiati, P., de Vries-Uiterweerd, G., Deyoung, T., Díaz-Vélez, J. C., Dierckxsens, M., Dreyer, J., Dumm, J. P., Duvoort, M. R., Ehrlich, R., Eisch, J., Ellsworth, R. W., Engdegård, O., Euler, S., Evenson, P. A., Fadiran, O., Fazely, A. R., Feusels, T., Filimonov, K., Finley, C., Foerster, M. M., Fox, B. D., Franckowiak, A., Franke, R., Gaisser, T. K., Gallagher, J., Geisler, M., Gerhardt, L., Gladstone, L., Glüsenkamp, T., Goldschmidt, A., Goodman, J. A., Grant, D., Griesel, T., Gross, A., Grullon, S., Gurtner, M., Ha, C., Hallgren, A., Halzen, F., Han, K., Hanson, K., Helbing, K., Herquet, P., Hickford, S., Hill, G. C., Hoffman, K. D., Homeier, A., Hoshina, K., Hubert, D., Huelsnitz, W., Hülss, J.-P., Hulth, P. O., Hultqvist, K., Hussain, S., Ishihara, A., Jacobsen, J., Japaridze, G. S., Johansson, H., Joseph, J. M., Kampert, K.-H., Karg, T., Karle, A., Kelley, J. L., Kemming, N., Kenny, P., Kiryluk, J., Kislat, F., Klein, S. R., Knops, S., Köhne, J.-H., Kohnen, G., Kolanoski, H., Köpke, L., Koskinen, D. J., Kowalski, M., Kowarik, T., Krasberg, M., Krings, T., Kroll, G., Kuehn, K., Kuwabara, T., Labare, M., Lafebre, S., Laihem, K., Landsman, H., Lauer, R., Lehmann, R., Lennarz, D., Lünemann, J., Madsen, Jens, Majumdar, P., Marotta, A., Maruyama, R., Mase, K., Matis, H. S., Matusik, M., Meagher, K., Merck, M., Mészáros, P., Meures, T., Middell, E., Milke, N., Miller, J., Montaruli, T., Morse, R., Movit, S. M., Nahnhauer, R., Nam, J. W., Naumann, U., Niessen, P., Nygren, D. R., Odrowski, S., Olivas, A., Olivo, M., O'Murchadha, A., Ono, M., Panknin, S., Paul, L., Pérez de Los Heros, C., Petrovic, J., Piegsa, A., Pieloth, D., Porrata, R., Posselt, J., Price, P. B., Prikockis, M., Przybylski, G. T., Rawlins, K., Redl, P., Resconi, E., Rhode, W., Ribordy, M., Rizzo, A., Rodrigues, J. P., Roth, P., Rothmaier, F., Rott, C., Roucelle, C., Ruhe, T., Rutledge, D., Ruzybayev, B., Ryckbosch, D., Sander, H.-G., Santander, M., Sarkar, S., Schatto, K., Schlenstedt, S., Schmidt, T., Schukraft, A., Schultes, A., Schulz, O., Schunck, M., Seckel, D., Semburg, B., Seo, S. H., Sestayo, Y., Seunarine, S., Silvestri, A., Slipak, A., Spiczak, G. M., Spiering, C., Stamatikos, M., Stanev, T., Stephens, G., Stezelberger, T., Stokstad, R. G., Stoyanov, S., Strahler, E. A., Straszheim, T., Sullivan, G. W., Swillens, Q., Taavola, H., Taboada, I., Tamburro, A., Tarasova, O., Tepe, A., Ter-Antonyan, S., Tilav, S., Toale, P. A., Toscano, S., Tosi, D., Turčan, D., van Eijndhoven, N., Vandenbroucke, J., van Overloop, A., van Santen, J., Voge, M., Voigt, B., Walck, C., Waldenmaier, T., Wallraff, M., Walter, M., Weaver, Ch., Wendt, C., Westerhoff, S., Whitehorn, N., Wiebe, K., Wiebusch, C. H., Wikström, G., Williams, D. R., Wischnewski, R., Wissing, H., Wolf, M., Woschnagg, K., Xu, C., Xu, X. W., Yodh, G., Yoshida, S., Zarzhitsky, P.
• Other Authors: Max-Planck-Institut für Kernphysik (MPIK), Max-Planck-Gesellschaft, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2010
• Subjects: cosmic rays; neutrinos; [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE]; [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE]; [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]; [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]; Antarc*; Antarctic
• Online Access: https://hal.in2p3.fr/in2p3-00706858; https://doi.org/10.1088/2041-8205/718/2/L194

We report the first observation of an anisotropy in the arrival direction of cosmic rays with energies in the multi-TeV region in the Southern sky using data from the IceCube detector. Between 2007 June and 2008 March, the partially deployed IceCube detector was operated in a configuration with 1320 digital optical sensors distributed over 22 strings at depths between 1450 and 2450 m inside the Antarctic ice. IceCube is a neutrino detector, but the data are dominated by a large background of cosmic-ray muons. Therefore, the background data are suitable for high-statistics studies of cosmic rays in the southern sky. The data include 4.3 billion muons produced by downward-going cosmic-ray interactions in the atmosphere; these events were reconstructed with a median angular resolution of 3° and a median energy of ~20 TeV. Their arrival direction distribution exhibits an anisotropy in right ascension with a first-harmonic amplitude of (6.4 ± 0.2 stat. ± 0.8 syst.) × 10-4.