Discovery of Localized Regions of Excess 10-TeV Cosmic Rays

Abstract

An analysis of 7 years of Milagro data performed on a 10-degree angular scale has found two localized regions of excess of unknown origin with greater than 12 sigma significance. Both regions are inconsistent with gamma-ray emission with high confidence. One of the regions has a different energy spectrum than the isotropic cosmic-ray flux at a level of 4.6 sigma, and it is consistent with hard spectrum protons with an exponential cutoff, with the most significant excess at ~10 TeV. Potential causes of these excesses are explored, but no compelling explanations are found.

Submitted to PhysRevLett

References in corpus (3)

• Anisotropy and Corotation of Galactic Cosmic Rays
• Discovery of TeV Gamma-Ray Emission from the Cygnus Region of the Galaxy
• The puzzling MILAGRO hot spots

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