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 ultrahigh-energy component requires a power-law index of the spectrum , s _ { cr } \approx 2.1 - 2.2 , somewhat harder than s _ { cr } \approx 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 .