Ultra-high energy cosmic rays detected by Auger and AGASA. Corrections for galactic magnetic field deflections, source populations, and arguments for multiple components. Astronomy and Astrophysics 523 A49

Context. The origin and composition of Ultra-High Energy Cosmic Ray Events (UHECRs) are under debate. Possible sources include Active Galactic Nuclei- selected by various criteria- and extragalactic magnetars. Aims. We aim to improve constraints on the source population(s) and compositions of UHECRs by accounting for UHECR deflections within existing Galactic magnetic field models (GMFs). Methods. We used Monte Carlo simulations for UHECRs detected by the Pierre Auger Observatory and AGASA, to determine the UHECR trajectories within the galaxy and their outside-the-Galaxy arrival directions. The simulations, which used UHECR compositions from protons to Iron and seven models of the ordered GMF, accounted for uncertainties in the GMF and a turbulent magnetic field component. The trajectories and outside-the-Galaxy arrival directions were compared with Galactic and extragalactic sources. Results. For a given proton or light UHECR, the multiple potential outside-the-Galaxy arrival directions within a given GMF model are not very different, allowing meaningful constraints on source populations. The correlation between a subset of UHECRs and nearby extended radiogalaxies (Nagar & Matulich 2008) remains valid, even strengthened, within several GMF models. Both the nearest radiogalaxy Cen A, and the nearest radio-extended BL Lac, CGCG 413−019, are potentially sources of multiple UHECRs. The correlation appears to be linked to the presence of the extended radio source rather than a tracer of an underlying matter distribution. Several UHECRs have trajectories which pass close to or through the Galactic plane, some passing close to Galactic magnetars and/or microquasars. For heavier UHECRs, the multipl