Ultra High Energy Γ-ray Research Articles

Ultra high energy cosmic rays and ultra high energy γ-rays

Evidence on the energy spectrum, mass composition and anisotropy of cosmic rays above 10 14 eV is briefly surveyed and it is shown that the data are consistent with all cosmic rays below 10 19 eV being of galactic origin. Results from the new field of γ-ray astronomy above 10 15 eV are described and implications for the origin of cosmic rays are discussed. It is argued that while shock acceleration can explain the cosmic ray beam below ∼2×10 15 eV, the spectrum up to 10 19 eV at the present time may be dominated by the output from a single accelerator (Cyg X-3 being the paradigm). Cosmic rays above 10 19 eV are probably of extra-galactic origin.

Ultra-High Energy γ-Rays from Intergalactic Space

Ultra-High Energy γ-Rays from Intergalactic Space