On the role of galactic magnetic halo in the ultra high energy cosmic rays propagation.
Résumé
The study of propagation of Ultra High Energy Cosmic Rays (UHECR) is a key step in order to unveil the secret of their origin. In this article we have focused our analysis on the influence of the magnetic field of the galaxies. We have used the most complete galaxy catalog up to now: the LEDA catalog with 60130 galaxies inside 120 Mpc. In our simulations we assign a Halo Dipole magnetic Field (HDF) to each galaxy. The HDF is a dipole magnetic field with cutoff lower value for $B = 0.1$~nG, which corresponds to a magnetized region of $\sim 100$~kpc. The code developed is able to retro-propagate a charged particle from the arrival points of UHECR data across our galaxies sample. We have shown that there is a non negligible deviation in the case of protons of $7\times 10^{19}$ eV, even if the $B$ value is conservative. We present simulations in case of Virgo cluster and we analyze the case of the AGASA triplet where we find NGC3998 and NGC3992 as possible candidates.