Source position reconstruction and constraints on the galactic magnetic field from ultra-high energy cosmic rays

We study the possibility to reconstruct the position of ultra-high energy cosmic ray sources and some properties of the magnetic field along the line of sight towards them in the case that several events from the same source are detected. By considering an illustrative model for the galactic magnetic field, including both a regular and a turbulent component, we estimate the accuracy that can be achieved in the reconstruction. We analyse the effect of the experimental energy and angular resolutions on these results. We show that if about 10 events with energies above 30 EeV are detected coming from the same source, it should be possible to reconstruct the source position with an accuracy of 0.5° and the integral of the orthogonal component of the magnetic field along the line of sight with an accuracy of 0.6 μ G kpc Z - 1 (with Z the electric charge of the particles).