Observation of Anisotropy in the Galactic Cosmic-Ray Arrival Directions at 400 TeV with IceCubeShow others and affiliations
2012 (English)In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 746, no 1Article in journal (Refereed) Published
Abstract [en]
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 x 10(9) muon events with a median angular resolution of similar to 3 degrees. 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 -6.3 sigma. 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.
Place, publisher, year, edition, pages
2012. Vol. 746, no 1
Keywords [en]
astroparticle physics, cosmic rays, neutrinos
National Category
Subatomic Physics
Research subject
Physics
Identifiers
URN: urn:nbn:se:su:diva-74243DOI: 10.1088/0004-637X/746/1/33ISI: 000302861300033Scopus ID: 2-s2.0-84863073281OAI: oai:DiVA.org:su-74243DiVA, id: diva2:507287
Projects
IceCube
Funder
Swedish Research CouncilKnut and Alice Wallenberg Foundation
Note
Publikationen har totalt 260 författare, R. Abbasi et al.
2012-03-032012-03-032022-10-03Bibliographically approved