Searches for Cosmic-Ray Electron Anisotropies with the Fermi Large Area Telescope

Abstract

The Large Area Telescope on board the \textit{Fermi} satellite (\textit{Fermi}-LAT) detected more than 1.6 million cosmic-ray electrons/positrons with energies above 60 GeV during its first year of operation. The arrival directions of these events were searched for anisotropies of angular scale extending from $\sim$ 10 ${}^{\circ }$ up to 90${}^{\circ }$, and of minimum energy extending from 60 GeV up to 480 GeV. Two independent techniques were used to search for anisotropies, both resulting in null results. Upper limits on the degree of the anisotropy were set that depended on the analyzed energy range and on the anisotropy's angular scale. The upper limits for a dipole anisotropy ranged from $\sim 0.5$ to $\sim 10$.

16 pages, 10 figures, accepted for publication in Physical Review D - contact authors: M.N. Mazziotta and V. Vasileiou

References in corpus (13)

• Observation of an anomalous positron abundance in the cosmic radiation
• Measurement of the Cosmic Ray e+ plus e- spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope
• Fermi LAT observations of cosmic-ray electrons from 7 GeV to 1 TeV
• On possible interpretations of the high energy electron-positron spectrum measured by the Fermi Large Area Telescope
• Anisotropy and Corotation of Galactic Cosmic Rays
• Discovery of Localized Regions of Excess 10-TeV Cosmic Rays
• The Large Scale Cosmic-Ray Anisotropy as Observed with Milagro
• Measurement of the Anisotropy of Cosmic Ray Arrival Directions with IceCube
• The PAMELA and ATIC Excesses From a Nearby Clump of Neutralino Dark Matter
• Cosmic ray lepton puzzle in the light of cosmological N-body simulations
• ATIC, PAMELA, HESS, Fermi and nearby Dark Matter subhalos
• The Contribution of Fermi Gamma-Ray Pulsars to the local Flux of Cosmic-Ray Electrons and Positrons
• Local dark matter clumps and the cosmic ray positron excess

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