Distortion of the ultrahigh energy cosmic ray flux from rare transient sources in inhomogeneous extragalactic magnetic fields

Abstract

Detecting and characterizing the anisotropy pattern of the arrival directions of the highest energy cosmic rays are crucial steps towards the identification of their sources. We discuss a possible distortion of the cosmic ray flux induced by the anisotropic and inhomogeneous distribution of extragalactic magnetic fields in cases where sources of ultrahigh energy cosmic rays are rare transient phenomena, such as gamma-ray bursts and/or newly born magnetars. This distortion does not involve an angular deflection but the modulation of the flux related to the probability of seeing the source on an experiment lifetime. To quantify this distortion, we construct sky maps of the arrival directions of these highest energy cosmic rays for various magnetic field configurations and appeal to statistical tests proposed in the literature. We conclude that this distortion cannot affect present experiments but should be considered when performing anisotropy studies with future large-scale experiments that record as many as hundreds of events above 6x10^19 eV.

9 pages, 6 figures, accepted by A&A

References in corpus (9)

• Cluster Magnetic Fields from Galactic Outflows
• Magnetic Field Seeding by Galactic Winds
• Ultra High Energy Cosmic Rays from Black Hole Jets of Radio Galaxies
• Anisotropy vs chemical composition at ultra-high energies
• The optical depth of the Universe to ultrahigh energy cosmic ray scattering in the magnetized large scale structure
• Searching for a Correlation Between Cosmic-Ray Sources Above 10^{19} eV and Large-Scale Structure
• Distortion of Ultra-high-energy sky by Galactic Magnetic Field
• Kolmogorov-Smirnov test as a tool to study the distribution of ultra-high energy cosmic ray sources
• The signature of local cosmic structures on the ultra-high energy cosmic ray anisotropies

Cited by in corpus (15)

• The Astrophysics of Ultrahigh Energy Cosmic Rays
• Indications of Intermediate-Scale Anisotropy of Cosmic Rays with Energy Greater Than 57 EeV in the Northern Sky Measured with the Surface Detector of the Telescope Array Experiment
• Open Questions in Cosmic-Ray Research at Ultrahigh Energies
• Newly-born pulsars as sources of ultrahigh energy cosmic rays
• UHECR acceleration at GRB internal shocks
• Ultrahigh energy cosmic ray acceleration in newly born magnetars and their associated gravitational wave signatures
• The Role of Structured Magnetic Fields on Constraining Properties of Transient Sources of Ultra-high-energy Cosmic Rays
• Anisotropy expectations for ultra-high-energy cosmic rays with future high statistics experiments
• Acceleration and propagation of ultra high energy cosmic rays
• Selected Topics in Cosmic Ray Physics
• Simulations for a next-generation UHECR observatory
• The Highest-Energy Cosmic Rays Cannot be Dominantly Protons from Steady Sources
• Constraints on the AGN flares as sources of ultra-high energy cosmic rays from the Fermi-LAT observations
• Revisiting Propagation Delays of Ultra-High-Energy Cosmic Rays from Long-lived Sources
• A lower bound on the number of cosmic ray events required to measure source catalogue correlations