Heidelberg 2022 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

T: Fachverband Teilchenphysik

T 19: Cosmic Ray 1

T 19.6: Vortrag

Montag, 21. März 2022, 17:35–17:50, T-H32

Effects of magnetic fields on anisotropies in the arrival direction of ultra-high-energy cosmic rays — •Luca Deval, Ralph Engel, Thomas Fitoussi, and Michael Unger — Karlsruhe Institute of Technology, Institut für Kernphysik, Karlsruhe, Germany

The source of ultra-high-energy cosmic rays (UHECRs) is still an open question in astrophysics. The latest analysis of the dataset from the Pierre Auger Observatory revealed presence of anisotropy in the arrival direction of UHECRs which is an indication of the signal contribution of nearby sources. A maximum likelihood analysis found a statistical significance of 4σ for the correlation of the measured arrival directions with a sample of nearby starbust galaxies (SBG). Although, the dependence of the galactic magnetic field (GMF), which is expected to have a key role in the arrival direction of charged particles, has not been considered.

In this work we present a study of the effects of the GMF on the arrival directions of particles related to different source populations, namely SBG and active galactic nuclei. We assume an injected cosmic ray spectrum with a mixed composition and a maximum rigidity. The extragalactic propagation is simulated with CRPropa3 while the deflections of cosmic rays in the Galaxy are calculated assuming the GMF model of Jansson&Farrar (2012). The obtained results show that it is possible to recover scenarios which are compatible with the results obtained by the Pierre Auger Collaboration although the signal fraction related to the source contribution has to be increased. Moreover no contribution of the extragalactic magnetic field is necessary.