OBSERVATION OF ANISOTROPY IN THE GALACTIC COSMIC-RAY ARRIVAL DIRECTIONS AT 400 TeV WITH ICECUBE
OBSERVATION OF ANISOTROPY IN THE GALACTIC COSMIC-RAY ARRIVAL DIRECTIONS AT 400 TeV WITH ICECUBE
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DOI：
10.1088/0004-637x/746/1/33
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发表时间：
2011-09
期刊：
影响因子：
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通讯作者：
R. Abbasi;Y. Abdou;T. Abu-Zayyad;M. Ackermann;J. Adams;J. Aguilar;M. Ahlers;M. Allen;D. Al
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文献类型：
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作者：
R. Abbasi;Y. Abdou;T. Abu-Zayyad;M. Ackermann;J. Adams;J. Aguilar;M. Ahlers;M. Allen;D. Al
在本文中，我们报告了南半球首次观测到银河宇宙射线各向异性的能量依赖性高达数百TeV。这项测量是利用部分部署的 IceCube 天文台在 2009 年 5 月至 2010 年 5 月期间记录的宇宙射线诱发 μ 子进行的。这些数据总共包括 33 × 109 μ 子事件，中位角分辨率为 ∼3°。给出了宇宙射线中值能量为 20 和 400 TeV 的南天天空到达方向相对强度的天空图。在 20 TeV 左右的中值能量处观察到的相同大尺度各向异性在 400 TeV 处并不存在。相反，高能天空图显示了不同的各向异性结构，包括试验后显着性为-6.3σ的赤字。这种各向异性揭示了银河系宇宙线分布的新特征，必须将其纳入宇宙线起源和传播理论中。
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 2009 May and 2010 May. The data include a total of 33 × 109 muon events with a median angular resolution of ∼3°. 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 sky map shows a different anisotropy structure including a deficit with a post-trial significance of −6.3σ. 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.