Large scale distribution of arrival directions of cosmic rays detected above $10^{18}$ eV at the Pierre Auger Observatory

Abstract

A thorough search for large scale anisotropies in the distribution of arrival directions of cosmic rays detected above $10^{18}$ eV at the Pierre Auger Observatory is presented. This search is performed as a function of both declination and right ascension in several energy ranges above $10^{18}$ eV, and reported in terms of dipolar and quadrupolar coefficients. Within the systematic uncertainties, no significant deviation from isotropy is revealed. Assuming that any cosmic ray anisotropy is dominated by dipole and quadrupole moments in this energy range, upper limits on their amplitudes are derived. These upper limits allow us to challenge an origin of cosmic rays above $10^{18}$ eV from stationary galactic sources densely distributed in the galactic disk and emitting predominantly light particles in all directions.

41 pages, 12 figures

References in corpus (8)

• Anisotropy and Corotation of Galactic Cosmic Rays
• The Large Scale Cosmic-Ray Anisotropy as Observed with Milagro
• Measurement of the Anisotropy of Cosmic Ray Arrival Directions with IceCube
• Evolution of the cosmic ray anisotropy above 10^{14} eV
• Constraints on the origin of cosmic rays above $10^{18}$ eV from large scale anisotropy searches in data of the Pierre Auger Observatory
• The Compton-Getting effect on ultra-high energy cosmic rays of cosmological origin
• Constraining warm dark matter with cosmic shear power spectra
• Estimates of multipolar coefficients to search for cosmic ray anisotropies with non-uniform or partial sky coverage

Cited by in corpus (10)

• Constraints on the origin of cosmic rays above $10^{18}$ eV from large scale anisotropy searches in data of the Pierre Auger Observatory
• Searches for Large-Scale Anisotropy in the Arrival Directions of Cosmic Rays Detected above Energy of $10^{19}$ eV at the Pierre Auger Observatory and the Telescope Array
• Escape model for Galactic cosmic rays and an early extragalactic transition
• A search for point sources of EeV photons
• A Targeted Search for Point Sources of EeV Neutrons
• Impact of atmospheric effects on the energy reconstruction of air showers observed by the surface detectors of the Pierre Auger Observatory
• Cosmic Rays around $10^{18}$eV: Implications of Contemporary Measurements on the Origin of the Ankle Feature
• Sensitivity of full-sky experiments to large scale cosmic ray anisotropies
• The Fortuitous Latitude of the Pierre Auger Observatory and Telescope Array for Reconstructing the Quadrupole Moment
• Large Scale Anisotropy of Cosmic Rays and Directional Neutrino Signals from Galactic Sources