Cosmic-Ray Anisotropy from Large Scale Structure and the effect of magnetic horizons

Understand

Motivated by the ~7 % dipole anisotropy in the distribution of ultra-high energy cosmic-rays (UHECRs) above 8 EeV, we explore the anisotropy induced by the large scale structure, using constrained simulations of the local Universe and taking into account the effect of magnetic fields.

• The value of the intergalactic magnetic field (IGMF) is critical as it determines the UHECR cosmic horizon.
• We calculate the UHECR sky maps for different values of the IGMF variance and show the effect of the UHECR horizon on the observed anisotropy.
• The footprint of the local ($\lesssim350$ Mpc) Universe on the UHECR background, a small angular scale enhancement in the Northern Hemisphere, is seen.