A synchrotron self-Compton emission model compared with the VHE spectrum of Crab Nebula, Geminga energy spectra and hadronic gamma-rays in the Tycho SNR

The Crab Nebula has an extraordinary broad spectrum, attributed to synchrotron radiation of electrons with energies from GeV to PeV. This continuous spectrum appears to terminate near 108 eV and photons, produced by relativistic electrons and positrons (∼1015 eV) via the Inverse Compton effect, form a new component of the spectrum in the GeV - TeV energy range. The spectrum of γ-rays from the Crab Nebula has been measured in the energy range 0.8 TeV to 11 TeV at the SHALON Alatoo Observatory by the atmospheric Cerenkov technique. The VHE spectral energy distribution of the Crab Nebula is compared with the predictions of a synchrotron self-Compton emission model in the energy range 0.8 TeV to 11 TeV (Hillas et al. 1998). Tycho's SNR has been observed by SHALON imaging Cherenkov telescope at Tien-Shan. This object, Ia SNR, has long been considered as a candidate for a CR hadron source in the Northern Hemisphere. The expected pion decay γ-flux, , extends up to >30 TeV, whereas the IC γ-ray flux has a cutoff above a few TeV. So, the detection of γ-rays at energies of 10 - 40 TeV by SHALON is evidence for a hadron origin of the γ-rays.