Abstract
We report on the observation of the large-scale sidereal anisotropy of Galactic Cosmic Rays (GCRs) at median energy of ∼300 TeV. With long time and high-stability collection by the Tibet air shower array between October 1995 and February 2010, the data used in this analysis contains 3.1×108 air shower events with a median angular resolution of 0.3◦. A new anisotropy structure at 300 TeV is revealed, which significantly deviates from the picture of cosmic ray isotropic intensity and is different with previous anisotropy observation at Multi-TeV energy. The dominant feature is an excess region that localized at (α = 271.0◦, δ = 22.1◦), with a significance of 7.3σ (pre-trial) or 5.4σ (post-trial) and an optimized smoothing of 29◦. The maximum relative intensity region with an intensity of ∼ 2.0 × 10− 3 is around (α = 255.0◦ , δ = −13.9◦), that is close to the highest excess region observed by IceCube at 400 TeV.
Original language | English |
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Title of host publication | Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013 |
Publisher | Sociedade Brasileira de Fisica |
Volume | 2013-October |
ISBN (Electronic) | 9788589064293 |
Publication status | Published - 2013 Jan 1 |
Event | 33rd International Cosmic Rays Conference, ICRC 2013 - Rio de Janeiro, Brazil Duration: 2013 Jul 2 → 2013 Jul 9 |
Other
Other | 33rd International Cosmic Rays Conference, ICRC 2013 |
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Country | Brazil |
City | Rio de Janeiro |
Period | 13/7/2 → 13/7/9 |
Keywords
- Anisotropy
- Cosmic rays
- Tibet AS Array
ASJC Scopus subject areas
- Nuclear and High Energy Physics