Ultra - high energy cosmic rays : are they isotropic ?
نویسنده
چکیده
From the analysis of AGASA data above 4 × 10 eV, we show that the ultra-high energy cosmic rays flux is neither purely isotropic, nor reflects the expected anisotropy from a pure source distribution that maps large scale structure in the local universe. The arrival distribution seems to be the result of a mixture of fluxes (e.g., dark matter halo plus large scale structure) or the superposition of a direct and a diffuse radiation field components respectively. Another viable option is an arbitrary extragalactic flux reprocessed by a magnetized galactic wind model as recently proposed in the literature. Subject headings: cosmology: dark matter — cosmology: large-scale structure of universe — Galaxy: halo — galaxies: magnetic fields — ISM: cosmic rays — ISM: magnetic fields
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