http://arxiv.org/abs/1903.05722
We study the effects that the diffusion of the cosmic rays in the magnetic field of the Local Supercluster can have on the spectrum of a nearby extragalactic source at ultra-high energies. We find that the strong enhancement of the flux below the energy at which the transition between the diffusive and quasi-rectilinear regimes takes place, as well as the suppression at lower energies associated with a finite source age, can help to explain the observed features of the cosmic-ray spectrum and the composition. Scenarios are discussed in which a nearby extragalactic source with mixed composition and rigidity-dependent spectrum accounts for most of the observed cosmic rays at energies above few EeV while the rest of the extragalactic sources lead to a diffuse flux that dominates at lower energies and down to $\sim 0.1$ EeV. The nearby source can also naturally account for the dipolar anisotropy measurements above 4 EeV.
S. Mollerach and E. Roulet
Fri, 15 Mar 19
44/67
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