| タイトル | Observation of an Anisotropy in the Galactic Cosmic Ray Arrival Direction at 400 TeV with IceCube |
| 著者（英） | Auffenberg, J.; Bay, R.; Bai, X.; Abbasi, R.; BenZvi, S.; Baker, M.; Berdermann, J.; Altmann, D.; Bazo Alba, J. L.; Beattie, K.; Ackermann, M.; Stamatikos, M.; Ahlers, M.; Becker, J. K.; Andeen, K.; Aguilar, J. A.; Beatty, J. J.; Barwick, S. W.; Adams, J.; Abdou, Y.; Bechet, S.; Becker, K. H.; Abu-Zayyad, T.; Benabderrahmane, M. L.; Allen, M. M. |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 2012-01-23 |
| 言語 | eng |
| 内容記述 | In this paper we report the first observation in the Southern hemisphere of an energy dependence in the Galactic cosmic ray anisotropy up to a few hundred TeV. This measurement was performed using cosmic ray induced muons recorded by the partially deployed IceCube observatory between May 2009 and May 2010. The data include a total of 33 x 10(exp 9) muon events with a median angular resolution of approx. 3 degrees. A sky map of the relative intensity in arrival direction over the Southern celestial sky is presented for cosmic ray median energies of 20 and 400 TeV. The same large-scale anisotropy observed at median energies around 20 TeV is not present at 400 TeV. Instead, the high energy skymap shows a different anisotropy structure including a deficit with a post-trial significance of -6.3 sigma. This anisotropy reveals a new feature of the Galactic cosmic ray distribution, which must be incorporated into theories of the origin and propagation of cosmic rays. |
| NASA分類 | Astronomy |
| レポートNO | GSFC.ABS..5857.2012 |
| 権利 | Copyright |
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