Cosmic rays from active galactic nuclei and in metagalactic space

Journal Article · Tue Feb 01 04:00:00 EST 1983 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/160700· OSTI ID:6081783

Shipiro, M M; Silberberg, R

Studies of extensive air showers have shown that cosmic rays at energies above 10/sup 19/ eV are likely to be extragalactic in origin. The energy density above 10/sup 19/ eV is 3 x 10/sup -8/ eV cm/sup -3/, and the exponent of the integral energy spectrum is -1.4 +- 0.1. For estimating the mean energy density of cosmic-ray protons in the supercluster, above 1 GeV, we also assume a power output for protons similar to that for relativistic electrons in active galactic nuclei. The mean energy density of relativistic electrons in the supercluster can be estimated from the nonthermal output of electromagnetic radiation. For cosmic rays in the supercluster, we obtain an energy density of 10/sup -4plus-or-minus1/ eV cm/sup -3/. Our estimate for this value is supported by the following internal consistency argument: the proton intensity at 10/sup 9/ eV (subject to the foregoing condition on power output), when extended with the exponent -1.4, smoothly joins the extragalactic spectrum at 10/sup 19/ eV, having the same slope. It is noteworthy that the exponent -1.4 is also that of galactic cosmic rays when corrected for rigidity-dependent leakage from the Galaxy.

• Research Organization: Laboratory for Cosmic Ray Physics, Naval Research Labaoratory, Washington, DC
• OSTI ID: 6081783
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 265:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics & Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BARYONS
COSMIC PROTONS
COSMIC RADIATION
COSMIC RAY SOURCES
ELEMENTARY PARTICLES
ENERGY DENSITY
FERMIONS
GALAXY CLUSTERS
GALAXY NUCLEI
HADRONS
IONIZING RADIATIONS
NUCLEONS
PROTONS
RADIATIONS