Constraining the Emissivity of Ultrahigh Energy Cosmic Rays in the Distant Universe with the Diffuse Gamma-ray Emission
arXiv:1103.3574 · doi:10.1088/0004-637X/736/2/112
Abstract
Ultra-high cosmic rays (UHECRs) with energies >10^19 eV emitted at cosmological distances will be attenuated by cosmic microwave and infrared background radiation through photohadronic processes. Lower energy extra-galactic cosmic rays (~10^18-10^19 eV) can only travel a linear distance smaller than ~Gpc in a Hubble time due to the diffusion if the extra-galactic magnetic fields are as strong as nano Gauss. These prevent us from directly observing most of the UHECRs in the universe, and thus the observed UHECR intensity reflects only the emissivity in the nearby universe within hundreds of Mpc. However, UHECRs in the distant universe, through interactions with the cosmic background photons, produce UHE electrons and gamma-rays that in turn initiate electromagnetic cascades on cosmic background photons. This secondary cascade radiation forms part of the extragalactic diffuse GeV-TeV gamma-ray radiation and, unlike the original UHECRs, is observable. Motivated by new measurements of extragalactic diffuse gamma-ray background radiation by Fermi/LAT, we obtained upper limits placed on the UHECR emissivity in the distant universe by requiring that the cascade radiation they produce not exceed the observed levels. By comparison with the gamma-ray emissivity of candidate UHECR sources (such as GRBs and AGNs) at high-redshifts, we find that the obtained upper limit for a flat proton spectrum is ~10^1.5 times larger than the gamma-ray emissivity in GRBs and ~10 times smaller than the gamma-ray emissivity in BL Lac objects. In the case of iron nuclei composition, the derived upper limit of the UHECR emissivity is a factor of 3-5 times higher. Robust upper limit on the cosmogenic neutrino flux is further obtained, which is marginally reachable by the Icecube detector and the next-generation detector JEM-EUSO.
arXiv comment14 pages, 8 figures, Replaced to match the published version
References in corpus (35)
- High Energy Neutrinos from Astrophysical Sources: An Upper Bound
- COSMOLOGICAL GAMMA RAY BURSTS AND THE HIGHEST ENERGY COSMIC RAYS
- Luminosity-dependent evolution of soft X-ray selected AGN: New Chandra and XMM-Newton surveys
- On the acceleration of Ultra High Energy Cosmic Rays in Gamma Ray Bursts
- Modeling the Extragalactic Background Light from Stars and Dust
- Measurement of the Depth of Maximum of Extensive Air Showers above 10^18 eV
- The Spectrum of the Isotropic Diffuse Gamma-Ray Emission Derived From First-Year Fermi Large Area Telescope Data
- On astrophysical solution to ultra high energy cosmic rays
- Neutrinos from propagation of ultra-high energy protons
- Monte-Carlo simulations of photohadronic processes in astrophysics
- Revealing the High-Redshift Star Formation Rate with Gamma-Ray Bursts
- Indications of Proton-Dominated Cosmic Ray Composition above 1.6 EeV
- GZK Neutrinos after the Fermi-LAT Diffuse Photon Flux Measurement
- On the Collapsar Model of Long Gamma-Ray Bursts: Constraints from Cosmic Metallicity Evolution
- High-energy cosmic-ray nuclei from high- and low-luminosity gamma-ray bursts and implications for multi-messenger astronomy
- Giant AGN Flares and Cosmic Ray Bursts
- The Luminosity and Angular Distributions of Long GRBs
- Constraints on the VHE Emissivity of the Universe from the Diffuse GeV Gamma-Ray Background
- An Unexpectedly Swift Rise in the Gamma-ray Burst Rate
- High-energy Cosmic Rays and Neutrinos from Semi-relativistic Hypernovae
- Restricting UHECRs and cosmogenic neutrinos with Fermi-LAT
- Extra-galactic magnetic fields and the second knee in the cosmic-ray spectrum
- On the Redshift Distribution of Gamma Ray Bursts in the Swift Era
- Cosmogenic Neutrinos from Ultra-High Energy Nuclei
- High-Energy Cosmic Rays from Gamma-Ray Bursts
- Point-like gamma ray sources as signatures of distant accelerators of ultra high energy cosmic rays
- Hard X-ray and Gamma-ray Emission Induced by Ultra-High Energy Protons in Cluster Accretion Shocks
- Neutrino diagnostics of ultra-high energy cosmic ray protons
- Enhanced Cosmological GRB Rates and Implications for Cosmogenic Neutrinos
- Acceleration of Ultra-High Energy Cosmic Rays in the Colliding Shells of Blazars and GRBs: Constraints from the Fermi Gamma ray Space Telescope
- TeV gamma-rays and neutrinos from photo-disintegration of nuclei in Cygnus OB2
- Cen A as TeV gamma-ray and possible UHE cosmic-ray source
- Ultra-High Energy Cosmic Rays and the GeV-TeV Diffuse Gamma-Ray Flux
- Detectability of ultrahigh energy cosmic ray signatures in gamma rays
- Limitations on the Photo-disintegration Process as a Source of VHE Photons
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- GeV Observations of Star-forming Galaxies with \textit{Fermi} LAT
- Constraining Very Heavy Dark Matter Using Diffuse Backgrounds of Neutrinos and Cascaded Gamma Rays
- Gamma-Ray and Neutrino Backgrounds as Probes of the High-Energy Universe: Hints of Cascades, General Constraints, and Implications for TeV Searches
- Active Galactic Nuclei under the scrutiny of CTA
- Gamma-Ray Constraints on Maximum Cosmogenic Neutrino Fluxes and UHECR Source Evolution Models
- The diffuse gamma-ray flux associated with sub-PeV/PeV neutrinos from starburst galaxies
- Cosmogenic neutrinos and ultra-high energy cosmic ray models
- Constraints on the origin of ultra-high-energy cosmic rays from cosmogenic neutrinos and photons
- Propagation of high-energy neutrinos in a background of ultralight scalar dark matter
- Constraints on the origin of the ultra-high energy cosmic-rays using cosmic diffuse neutrino flux limits: An analytical approach
- Indication of a Local "Fog" of Sub-Ankle UHECR
- Acceleration and propagation of ultra high energy cosmic rays
- Origin of Ultrahigh Energy Galactic Cosmic Rays: The Isotropy Problem
- Characterising the signatures of star-forming galaxies in the extra-galactic -ray background
- Selected Topics in Cosmic Ray Physics
- Effects of large-scale magnetic fields on the observed composition of ultra high-energy cosmic rays
- Ultra high-energy cosmic rays from beyond the Greisen-Zatsepin-Kuz'min horizon
- High-Energy Neutrino Production in Clusters of Galaxies