Probing the Extragalactic Cosmic-Ray Origin with Gamma-Ray and Neutrino Backgrounds

Journal Article · Thu Apr 20 04:00:00 EDT 2017 · Astrophysical Journal Letters

DOI:https://doi.org/10.3847/2041-8213/AA6AF0· OSTI ID:22654491

Globus, Noemie; Piran, Tsvi ^[1]; Allard, Denis; Parizot, Etienne ^[2]

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1. Racah Institute of Physics, The Hebrew University, 91904 Jerusalem (Israel)
2. Laboratoire Astroparticule et Cosmologie, Université Paris Diderot/CNRS, 10 rue A. Domon et L. Duquet, F-75205 Paris Cedex 13 (France)

GeV–TeV gamma-rays and PeV–EeV neutrino backgrounds provide a unique window on the nature of the ultra-high-energy cosmic rays (UHECRs). We discuss the implications of the recent Fermi -LAT data regarding the extragalactic gamma-ray background and related estimates of the contribution of point sources as well as IceCube neutrino data on the origin of the UHECRs. We calculate the diffuse flux of cosmogenic γ -rays and neutrinos produced by the UHECRs and derive constraints on the possible cosmological evolution of UHECR sources. In particular, we show that the mixed-composition scenario considered in Globus et al., which is in agreement with both (i) Auger measurements of the energy spectrum and composition up to the highest energies and (ii) the ankle-like feature in the light component detected by KASCADE-Grande, is compatible with both the Fermi -LAT measurements and with current IceCube limits. We also discuss the possibility for future experiments to detect associated cosmogenic neutrinos and further constrain the UHECR models, including possible subdominant UHECR proton sources.

• OSTI ID: 22654491
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 839; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COSMIC RADIATION
EEV RANGE
ENERGY SPECTRA
EVOLUTION
GAMMA RADIATION
GEV RANGE
ICECUBE NEUTRINO DETECTOR
LIMITING VALUES
NEUTRINOS
ORIGIN
PEV RANGE
POINT SOURCES
PROTON SOURCES
PROTONS
TEV RANGE
VISIBLE RADIATION