  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, $s_{\rm cr}\approx2.1-2.2$, somewhat harder than $s_{\rm
cr}\approx2.3-2.4$ 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.
