The large-scale anisotropy and flux (de-)magnification of ultra-high-energy cosmic rays in the Galactic magnetic field

Abstract

We calculate the arrival direction distribution of ultra-high-energy cosmic rays (UHECRs) with a new suite of models of the Galactic magnetic field (GMF), assuming sources follow the large-scale structure of the Universe. Compared to previous GMF models, the amplitude of the dipole component of the UHECR arrival flux is significantly reduced. We find that the reduction is due to the accidentally coinciding position of the peak of the extragalactic UHECR flux and the boundary of strong flux demagnification due to the GMF toward the central region of the Galaxy. This serendipitous sensitivity of UHECR anisotropies to the GMF model will be a powerful probe of the source distribution as well as Galactic and extragalactic magnetic fields. Demagnification by the GMF also impacts visibility of some popular source candidates.

References in corpus (39)

• GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo During the Second Part of the Third Observing Run
• Nuclear Activity in Nearby Galaxies
• The Pierre Auger Cosmic Ray Observatory
• On the fundamental dichotomy in the local radio-AGN population: accretion, evolution, and host galaxy properties
• A New Model of the Galactic Magnetic Field
• The Herschel PEP/HerMES Luminosity Function. I: Probing the Evolution of PACS selected Galaxies to z~4
• Observation of a Large-scale Anisotropy in the Arrival Directions of Cosmic Rays above $8\times 10^{18}$ eV
• The Galactic Magnetic Field
• The luminosity function and the rate of Swift's Gamma Ray Bursts
• Depth of Maximum of Air-Shower Profiles at the Pierre Auger Observatory: Composition Implications
• The Cosmic Evolution of Fermi BL Lacertae Objects
• Measurement of the cosmic-ray energy spectrum above $2.5\times 10^{18}$ eV using the Pierre Auger Observatory
• The Evolution of Galaxy Number Density at z < 8 and its Implications
• Measurement of the rate of stellar tidal disruption flares
• Large-scale cosmic-ray anisotropies above 4 EeV measured by the Pierre Auger Observatory
• A very luminous jet from the disruption of a star by a massive black hole
• Lensing of ultra-high energy cosmic rays in turbulent magnetic fields
• Arrival Directions of Cosmic Rays above 32 EeV from Phase One of the Pierre Auger Observatory
• The Coherent Magnetic Field of the Milky Way
• Energetics of High-Energy Cosmic Radiations
• Constraining the sources of ultra-high-energy cosmic rays across and above the ankle with the spectrum and composition data measured at the Pierre Auger Observatory
• Fornax A, Centaurus A and other radio galaxies as sources of ultra-high energy cosmic rays
• Signatures of galactic magnetic lensing upon ultra high energy cosmic rays
• The Imprint of Large Scale Structure on the Ultra-High-Energy Cosmic Ray Sky
• Practical Modeling of Large-Scale Galactic Magnetic Fields: Status and Prospects
• An upper limit on the strength of the extragalactic magnetic field from ultra-high-energy cosmic-ray anisotropy
• Deflections of UHECRs in the Galactic magnetic field
• Constraining models for the origin of ultra-high-energy cosmic rays with a novel combined analysis of arrival directions, spectrum, and composition data measured at the Pierre Auger Observatory
• The quasi-linear nearby Universe
• How isotropic can the UHECR flux be?
• What can be learnt from UHECR anisotropies observations? Paper I : large-scale anisotropies and composition features
• Cosmic-Ray Anisotropy from Large Scale Structure and the effect of magnetic horizons
• The Nuclear Window to the Extragalactic Universe
• Curious case of the maximum rigidity distribution of cosmic-ray accelerators
• Impact of Galaxy Clusters on UHECR propagation
• Constraints on UHECR sources and extragalactic magnetic fields from directional anisotropies
• Galactic Magnetic Field Bias on Inferences from UHECR Data
• Treasure Maps for Detections of Extreme Energy Cosmic Rays
• Modification of the Dipole in Arrival Directions of Ultra-high-energy Cosmic Rays due to the Galactic Magnetic Field

Cited by in corpus (3)

• A Heavy-Metal Scenario of Ultra-High-Energy Cosmic Rays
• Effects of extragalactic magnetic field on the spectra of ultra-high-energy cosmic rays from jetted sources
• Revisiting Propagation Delays of Ultra-High-Energy Cosmic Rays from Long-lived Sources