Supernova remnants (SNRs) are widely considered the most likely source of cosmic rays below the knee ($10^{15}$ eV). Studies of GeV and TeV gamma-ray emission in the vicinity of SNRs, in combination with multi-wavelength observations, can trace and constrain the nature of the charged particle population believed to be accelerated within SNR shocks. They may also speak to the diffusion and propagation of these energetic particles and to the nature of the acceleration mechanisms involved. We report here on the discoveries and interpretation of VHE gamma-ray emission from G120.1+1.4 (Tychos SNR) and from the northwest shell of G78.2+2.1 (gamma-ray source VER J2019+407, which was discovered as a consequence of the VERITAS Cygnus region survey).
Download