2020/12/31 by Rodrigo Guedes Lang, Andrew M. Taylor, Vitor de Souza +1
Physics and Astronomy · #Astrophysics #Astrophysics and Cosmic Phenomena #Atomic physics #Auger #Computational physics #Cosmic ray #Dark Matter and Cosmic Phenomena #Dipole #Magnetic dipole #Magnetic field #Neutrino Physics Research #Physics #Pierre Auger Observatory #Quantum mechanics #Range (aeronautics) #Ultra-high-energy cosmic ray #astro-ph.HE
paper · pdf · doi:10.1103/physrevd.103.063005
openalex publication_date 2021/03/03 · arxiv created 2021/03/08 · arxiv updated 2021/03/09 · openalex created_date 2021/03/15 · openalex updated_date 2026/08/05
Recent data from the Pierre Auger Observatory has revealed the presence of a large-scale dipole in the arrival direction distribution of ultrahigh-energy cosmic rays (UHECR). In this work, we build up an understanding of the diffusive origin of such a dipolar behavior as well as its dependency on energy and astrophysical source assumptions such as extra-Galactic magnetic field strength and cosmic ray composition. We present a novel analytical approach for calculating the angular distribution of CR coming from a single source and discuss the regimes in which the steady-state dipole result is expected. We also present a semianalytical method for calculating the evolution with energy of the resultant dipole for an ensemble of sources. We show that a local source allows for a strong growth of the dipole with energy over a large energy range. The possibility of a transition from a dipolar to nondipolar regime at the highest energies and its implications for the source density, magnetic field intensity, and cosmic ray composition are discussed.