Mapping deflections of extragalactic ultrahigh-energy cosmic rays in magnetohydrodynamic simulations of the local universe

We construct a map of deflections of ultrahigh-energy cosmic rays by extragalactic magnetic fields using a magnetohydrodynamical simulation of cosmic structure formation that realistically reproduces the positions of known galaxy clusters in the Local Universe. Large deflection angles occur in cluster regions, which, however, cover only an insignificant fraction of the sky. More typical deflections of order ≲1° are caused by crossings of filaments. For protons with energies E ≥4×10 19 eV, deflections do not exceed a few degrees over most of the sky up to a propagation distance of 500 Mpc. Given that the field strength of our simulated intergalactic magnetic field forms a plausible upper limit, we conclude that charged particle astronomy is in principle possible.