Measurement of the Anisotropy of Cosmic Ray Arrival Directions with IceCube

TY - JOUR

T1 - Measurement of the Anisotropy of Cosmic Ray Arrival Directions with IceCube

AU - IceCube Collaboration, The

AU - Abbasi, R.

AU - Abdou, Y.

AU - Abu-Zayyad, T.

AU - Admas, J.

AU - Koskinen, David Jason

PY - 2010/8/1

Y1 - 2010/8/1

N2 - We report the first observation of an anisotropy in the arrival direction of cosmic rays with energies in the multi-TeV region in theSouthern 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 over22 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 aresuitable 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° and a median energy of ∼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.) × 10-4.

AB - We report the first observation of an anisotropy in the arrival direction of cosmic rays with energies in the multi-TeV region in theSouthern 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 over22 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 aresuitable 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° and a median energy of ∼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.) × 10-4.

KW - astro-ph.HE

U2 - 10.1088/2041-8205/718/2/L194

DO - 10.1088/2041-8205/718/2/L194

M3 - Journal article

SN - 2041-8205

VL - 718

JO - The Astrophysical Journal Letters

JF - The Astrophysical Journal Letters

IS - 2

M1 - L194

ER -