"We propose to develop a new analysis approach for charged particleastronomy to find the astrophysical sources of cosmic particles withextreme energies.During the recent years, there has been a rapid progress in ourunderstanding of Galactic magnetic field (GMF) and the collectedstatistics of ultra-high energy cosmic ray events. It should thereforebe possible to correct the measured arrival directions of cosmic rayson Earth for deflections in the GMF and to significantly improve thesearch for their astrophysical sources in this way. The researchobjectives of this proposal are therefore: 1) A thorough evaluation ofthe uncertainties of the GMF with the aim of producing sky maps of thedeflection uncertainty of cosmic rays given their arrival directionand rigidity (= energy divided by charge). 2) Development of an optimalanalysis method for correlation studies that takes into account thedeflection uncertainties originating from the uncertainties in both,GMF and the estimated rigidities. 3) Application of the optimal dataanalysis method to data of the Pierre Auger Observatory.During the outgoing phase, the fellow will join the astrophysics groupof the New York University to acquire state-of-the art knowledge onthe interpretation of astrophysical data relevant for the GMF.At the return host, the Karlsruher Institute ofTechnology, he will apply the obtained knowledge to data of thePierre Auger Observatory.This project will allow the fellow to be trained in the theoreticalfoundations and computational tools needed to study the GMF.It will broaden his knowledge in astrophysics andtherefore complement his current expertise of the particle physics ofair showers. The interdisciplinary training and the possibility togain teaching experience at both hosts, will contribute to thelong-term development of the fellow’s career and make him eligiblefor a leading academic position in Europe."