Northern Sky Galactic Cosmic Ray Anisotropy between 10 and 1000 TeV with the Tibet Air Shower Array
- Department of Physics, Hirosaki University, Hirosaki 036-8561 (Japan)
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)
- National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)
- Department of Mathematics and Physics, Tibet University, Lhasa 850000 (China)
- Department of Physics, Hebei Normal University, Shijiazhuang 050016 (China)
- Department of Physics, Shandong University, Jinan 250100 (China)
- Institute of Modern Physics, Southwest Jiaotong University, Chengdu 610031 (China)
- Faculty of Engineering, Kanagawa University, Yokohama 221-8686 (Japan)
- Faculty of Education, Utsunomiya University, Utsunomiya 321-8505 (Japan)
We report on the analysis of the 10–1000 TeV large-scale sidereal anisotropy of Galactic cosmic rays (GCRs) with the data collected by the Tibet Air Shower Array from 1995 October to 2010 February. In this analysis, we improve the energy estimate and extend the decl. range down to −30°. We find that the anisotropy maps above 100 TeV are distinct from that at a multi-TeV band. The so-called tail-in and loss-cone features identified at low energies get less significant, and a new component appears at ∼100 TeV. The spatial distribution of the GCR intensity with an excess (7.2 σ pre-trial, 5.2 σ post-trial) and a deficit (−5.8 σ pre-trial) are observed in the 300 TeV anisotropy map, in close agreement with IceCube’s results at 400 TeV. Combining the Tibet results in the northern sky with IceCube’s results in the southern sky, we establish a full-sky picture of the anisotropy in hundreds of TeV band. We further find that the amplitude of the first order anisotropy increases sharply above ∼100 TeV, indicating a new component of the anisotropy. All these results may shed new light on understanding the origin and propagation of GCRs.
- OSTI ID:
- 22663792
- Journal Information:
- Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 836; ISSN ASJOAB; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
OBSERVATION OF TeV GAMMA RAYS FROM THE FERMI BRIGHT GALACTIC SOURCES WITH THE TIBET AIR SHOWER ARRAY
All-sky Measurement of the Anisotropy of Cosmic Rays at 10 TeV and Mapping of the Local Interstellar Magnetic Field