Caustic-like Structures in UHECR Flux after Propagation in Turbulent Intergalactic Magnetic Fields and the caused distortions of the image of a source

International audience ; UHECR propagation in a turbulent intergalactic magnetic field in the small-angle scattering regime is well understood for propagation distances much larger than the field coherence scale. The diffusion theory doesn't work and unexpected effects may appear for propagation over smaller distances, from a few and up to 10-20 coherence scales. We study the propagation of UHECRs in this regime, which may be relevant for intermediate mass UHECR nuclei and nG scale intergalactic magnetic fields with 1 Mpc coherence scale. We found that the trajectories form a non-trivial caustic-like pattern with strong deviation from isotropy. In this regime we've found different observable cases of distortions of the source energy spectrum and the images of a source. Thus, measurements of the flux, direction and energy spectrum from a source at a given distance will depend on the position of the observer. In the future, these facts may explain Telescope Array observations.