MEASUREMENT OF THE ANISOTROPY OF COSMIC-RAY ARRIVAL DIRECTIONS WITH ICECUBE

作者：Abbasi R^*; Abdou Y; Abu Zayyad T; Adams J; Aguilar J A; Ahlers M; Andeen K; Auffenberg J; Bai X; Baker M; Barwick S W; Bay R; Alba J L Bazo; 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; Boeser S; Botner O; Bradley L; Braun J; Buitink S; Carson M; Chirkin D

来源：Astrophysical Journal Letters, 2010, 718(2): L194-L198.

DOI：10.1088/2041-8205/718/2/L194

• cosmic rays
• neutrinos

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 degrees and a median energy of similar to 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.) x 10(-4).

• 出版日期2010-8-1