https://doi.org/10.1140/epjc/s10052-021-09575-x
Regular Article - Experimental Physics
Towards extracting cosmic magnetic field structures from cosmic-ray arrival directions
RWTH Aachen University, III. Physikalisches Institut A, Otto-Blumenthal-Str., 52074, Aachen, Germany
Received:
6
December
2020
Accepted:
25
August
2021
Published online:
7
September
2021
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 method can be used to obtain information on the Galactic magnetic field, in particular the integrated component perpendicular to the line of sight, from cosmic-ray data only. Using a likelihood-ratio approach, neighboring cosmic rays are related by rotatable, elliptically shaped density distributions and the significance of their alignment with respect to circular distributions is evaluated. In this way, a vector field tangential to the celestial sphere is fitted which approximates the local deflections in cosmic magnetic fields if significant deflection structures are detected. The sensitivity of the method is evaluated on the basis of astrophysical simulations of the ultra-high energy cosmic-ray sky, where a discriminative power between isotropic and signal-induced scenarios is found.
© The Author(s) 2021
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Funded by SCOAP3
