https://doi.org/10.1051/epjconf/202328303008
Sensitivity of the combined fit of energy spectrum, shower depth distributions, and arrival directions at the Pierre Auger Observatory
1 Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud Universiteit, Nijmegen, Netherlands
2 Physics Institute IIIA, RWTH Aachen University, Otto-Blumenthal-Str., 52074 Aachen, Germany
* Corresponding author: teresa.bister@ru.nl
** Corresponding author: spokespersons@a uge r.org; full author list: https://auger.orgiarchive/authors_2022_10.html
Published online: 28 April 2023
The Pierre Auger Observatory measures several characteristics of ultra-high-energy cosmic rays (UHECRs), most importantly the energy spectrum, the distribution of maximum shower depths and the arrival directions. We use all three observables for a combined fit, in which parameters of possible UHECR sources can be constrained. The astrophy sical model used in the fit consists of homogeneo usly distributed background sources as well as an adaptable contribution from a nearby source population . For this, the catalogs of starburst galaxies and active galactic nuclei are used which show an indication for a correlation with the UHECR arrival directions . The signal fraction, as well as the size of a rigidity-dependent magn etic field blurring, are part of the fit parameters, along with the parameters describing the source emission. Tn this work, we present an astro-physical simulation containing an energy-dependent contribution from starburst galaxies, which simultaneously describes the energy spectrum, shower depth distributions, and arrival directions measured by the Pierre Auger Observatory. On this simulation, the discrimination power of the method regarding the differentiation of source catalogs is demonstrated, and the expected statistical significance of the result is investigated.
© The Authors, published by EDP Sciences, 2023
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
