A nearby source of ultra-high energy cosmic rays

Abstract

Recently the Telescope Array collaboration reported an observation of cosmic ray event with very high energy 244 EeV ($2.44\times 10^{20}$ eV). Importantly, the event is hard to correlate with the matter distribution in the local Universe, even after taking into account deflections in magnetic fields. This implies that the event is likely a nucleus with a large charge. An attenuation length of the nucleus of such a high energy in intergalactic space is quite small, therefore its source should be relatively close to our Galaxy. Using these arguments we derive a new upper bound on a distance to the closest ultra-high energy cosmic ray (UHECR) source and a lower bound on the UHECR source number density in general. The distance to the closest source should not exceed 5 Mpc at 95% C.L. and the 95% C.L. lower-bound on the sources number density is $\rho >1.0\times 10^{-4}$ Mpc${}^{-3}$. The number density of UHECR sources emitting heavy nuclei is constrained for the first time.

arXiv commentAccepted for publication in JCAP

References in corpus (23)

• The 2MASS Redshift Survey - Description and Data Release
• A New Model of the Galactic Magnetic Field
• Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory
• Deriving global structure of the Galactic Magnetic Field from Faraday Rotation Measures of extragalactic sources
• Indication of anisotropy in arrival directions of ultra-high-energy cosmic rays through comparison to the flux pattern of extragalactic gamma-ray sources
• Open Questions in Cosmic-Ray Research at Ultrahigh Energies
• The extragalactic background light revisited and the cosmic photon-photon opacity
• New limits on extragalactic magnetic fields from rotation measures
• A Lower-Limit Flux for the Extragalactic Background Light
• Physical conditions in potential sources of ultra-high-energy cosmic rays: Updated Hillas plot and radiation-loss constraints
• Arrival Directions of Cosmic Rays above 32 EeV from Phase One of the Pierre Auger Observatory
• The Coherent Magnetic Field of the Milky Way
• An extremely energetic cosmic ray observed by a surface detector array
• 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
• Bounds on the density of sources of ultra-high energy cosmic rays from the Pierre Auger Observatory
• Mapping UHECRs deflections through the turbulent galactic magnetic field with the latest RM data
• Revisiting the distance to the nearest UHECR source: Effects of extra-galactic magnetic fields
• Search for Spatial Correlations of Neutrinos with Ultra-High-Energy Cosmic Rays
• Where Did the Amaterasu Particle Come From?
• Flux calculations in an inhomogeneous Universe: weighting a flux-limited galaxy sample
• UHECR mass composition at highest energies from anisotropy of their arrival directions
• General constraints on sources of high-energy cosmic rays from the interaction losses
• The 320 EeV Fly's Eye event: a key messenger or a statistical oddity ?

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• Ultra-high energy event KM3-230213A as a cosmogenic neutrino in light of minimal UHECR flux models
• An isotropic full-sky sample of optically selected blazars
• Beyond the Local Void: A data-driven search for the origins of the Amaterasu particle
• Insights on the mass composition of ultrahigh-energy cosmic rays from small-scale anisotropy with large-scale structure simulations