Implications to Sources of Ultra-high-energy Cosmic Rays from their Arrival Distribution

Abstract

We estimate the local number density of sources of ultra-high-energy cosmic rays (UHECRs) based on the statistical features of their arrival direction distribution. We calculate the arrival distributions of protons above $10^{19}$ eV taking into account their propagation process in the Galactic magnetic field and a structured intergalactic magnetic field, and statistically compare those with the observational result of the Pierre Auger Observatory. The anisotropy in the arrival distribution at the highest energies enables us to estimate the number density of UHECR sources as $\sim 10^{-4}{\mathrm{Mpc}}^{-3}$ assuming the persistent activity of UHECR sources. We compare the estimated number density of UHECR sources with the number densities of known astrophysical objects. This estimated number density is consistent with the number density of Fanaroff-Reily I galaxies. We also discuss the reproducability of the observed {\it isotropy} in the arrival distribution above $10^{19}$ eV. We find that the estimated source model cannot reproduce the observed isotropy. However, the observed isotropy can be reproduced with the number density of $10^{-2}$-$10^{-3}{\mathrm{Mpc}}^{-3}$. This fact indicates the existence of UHECR sources with a maximum acceleration energy of $\sim 10^{19}$ eV whose number density is an order of magnitude more than that injecting the highest energy cosmic rays.

15 pages, 4 figures

References in corpus (26)

• Correlation of the highest energy cosmic rays with nearby extragalactic objects
• First Observation of the Greisen-Zatsepin-Kuzmin Suppression
• Extension of the Cosmic-Ray Energy Spectrum Beyond the Predicted Greisen-Zatsepin-Kuz'min Cutoff
• Origin and Propagation of Extremely High Energy Cosmic Rays
• The PSCz Catalogue
• Small-scale anisotropy of cosmic rays above 10^19eV observed with the Akeno Giant Air Shower Array
• Correlation of the highest-energy cosmic rays with the positions of nearby active galactic nuclei
• Energy determination in the Akeno Giant Air Shower Array experiment
• Measurement of the Flux of Ultrahigh Energy Cosmic Rays from Monocular Observations by the High Resolution Fly's Eye Experiment
• Ultra high energy cosmic rays and the large scale structure of the galactic magnetic field
• Cosmic Ray Anisotropy Analysis with a Full-Sky Observatory
• Astrophysical Origins of Ultrahigh Energy Cosmic Rays
• Cluster Accretion Shocks as Possible Acceleration Sites for Ultra High Energy Protons below the Greisen Cutoff
• The Luminosity Function of IRAS PSCz Galaxies
• Statistical Properties of Radio Emission from the Palomar Seyfert Galaxies
• Study of Small-Scale Anisotropy of Ultrahigh Energy Cosmic Rays Observed in Stereo by HiRes
• Hard X-ray and Gamma-ray Emission Induced by Ultra-High Energy Protons in Cluster Accretion Shocks
• Signatures of the Origin of High-Energy Cosmic Rays in Cosmological Gamma-Ray Bursts
• Searching for a Correlation Between Cosmic-Ray Sources Above 10^{19} eV and Large-Scale Structure
• The Small Scale Anisotropies, the Spectrum and the Sources of Ultra High Energy Cosmic Rays
• The Signature of a Correlation between $>10^{19}\mathrm{eV}$ Cosmic Ray Sources and Large Scale Structure
• Small Scale Clustering in the Isotropic Arrival Distribution of Ultra-High Energy Cosmic Rays and Implications for Their Source Candidates
• Propagation of Ultra-High Energy Cosmic Rays above $10^{19}$ eV in a Structured Extragalactic Magnetic Field and Galactic Magnetic Field
• Ultra-high energy cosmic rays from a finite number of point sources
• Distortion of Ultra-high-energy sky by Galactic Magnetic Field
• Estimation Prospects of the Source Number Density of Ultra-high-energy Cosmic Rays

Cited by in corpus (20)

• Blazars as Ultra-High-Energy Cosmic-Ray Sources: Implications for TeV Gamma-Ray Observations
• Ultrahigh-energy Cosmic-ray Nuclei from Black Hole Jets: Recycling Galactic Cosmic Rays through Shear Acceleration
• Bounds on the density of sources of ultra-high energy cosmic rays from the Pierre Auger Observatory
• Acceleration of Ultra-High Energy Cosmic Rays in the Colliding Shells of Blazars and GRBs: Constraints from the Fermi Gamma ray Space Telescope
• Heavy Nuclei Synthesized in Gamma-Ray Burst Outflows as the Source of UHECRs
• On the Possible Association of Ultra High Energy Cosmic Rays with Nearby Active Galaxies
• Radio Quiet AGNs as Possible Sources of Ultra-high Energy Cosmic Rays
• Identifying Ultrahigh-Energy Cosmic-Ray Accelerators with Future Ultrahigh-Energy Neutrino Detectors
• Ultrahigh-Energy Cosmic Ray Production by Turbulence in Gamma-Ray Burst Jets and Cosmogenic Neutrinos
• Cross-Correlation between UHECR Arrival Distribution and Large-Scale Structure
• The Role of Structured Magnetic Fields on Constraining Properties of Transient Sources of Ultra-high-energy Cosmic Rays
• Does Galactic Magnetic Field Disturb the Correlation of the Highest Energy Cosmic Rays with their Sources?
• Propagation of Ultra-High-Energy Cosmic Ray Nuclei in Cosmic Magnetic Fields and Implications for Anisotropy Measurements
• On ultra-high energy cosmic rays: origin in AGN jets and transport in expanding Universe
• Isotropy constraints on powerful sources of ultrahigh-energy cosmic rays at $10^{19}$ eV
• Constraining photohadronic scenarios for the unified origin of IceCube neutrinos and ultrahigh-energy cosmic rays
• A global autocorrelation study after the first Auger data: impact on the number density of UHECR sources
• Bounds on the origin of extragalactic ultrahigh energy cosmic rays from the IceCube neutrino observations
• Inverse problem for extragalactic transport of ultra-high energy cosmic rays
• On Estimating the Flux of the Brightest Cosmic Ray Source above 57x10^18 eV