Towards extracting cosmic magnetic field structures from cosmic-ray arrival directions

Abstract We present a novel method to search for structures of coherently aligned patterns in ultra-high energy cosmic-ray arrival directions simultaneously across the entire sky. This can be used obtain information on Galactic magnetic field, particular integrated component perpendicular line sight, from data only. Using likelihood-ratio approach, neighboring cosmic rays are related by rotatable, elliptically shaped density distributions and significance their alignment with respect circular is evaluated. In this way, vector field tangential celestial sphere fitted which approximates local deflections fields if significant deflection detected. The sensitivity evaluated basis astrophysical simulations sky, where discriminative power between isotropic signal-induced scenarios found.