Energetics of high-energy cosmic radiations

Kohta Murase, Masataka Fukugita

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33 Scopus citations


The luminosity densities of high-energy cosmic radiations are studied to find connections among the various components, including high-energy neutrinos measured with IceCube and gamma rays with the Fermi satellite. Matching the cosmic-ray energy generation rate density in a GeV-TeV range estimated for Milky Way with the ultra-high-energy component requires a power-law index of the spectrum scr≈2.1-2.2, somewhat harder than scr≈2.3-2.4 for the local index derived from the AMS-02 experiment. The soft GeV-TeV cosmic-ray spectrum extrapolated to higher energies can be compatible with PeV cosmic rays inferred from neutrino measurements, but overshoots the CR luminosity density to explain GeV-TeV gamma rays. The extrapolation from ultrahigh energies with a hard spectrum, on the other hand, can be consistent with both neutrinos and gamma rays. These point towards either reacceleration of galactic cosmic rays or the presence of extragalactic sources with a hard spectrum. We discuss possible cosmic-ray sources that can be added.

Original languageEnglish (US)
Article number063012
JournalPhysical Review D
Issue number6
StatePublished - Mar 15 2019

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)


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