Evidence of 200 TeV Photons from HAWC J1825-134

The Earth is bombarded by ultrarelativistic particles, known as cosmic rays (CRs). CRs with energies up to a few PeV (=1015 eV), the knee in particle spectrum, are believed have Galactic origin. One or more factories of CRs, PeVatrons, must thus be active within our Galaxy. direct detection protons from their sources not possible since they deflected magnetic fields. Hundred TeV ?-rays decaying ?0, produced when collide ambient gas, can provide decisive evidence proton acceleration knee. Here we report discovery High Altitude Water Cerenkov (HAWC) observatory ?-ray source, HAWC J1825-134, whose energy spectrum extends well beyond 200 without break cutoff. source found coincident giant molecular cloud. gas density high 700 cm?3. While nature this extreme accelerator remains unclear, accelerated several colliding likely produce observed radiation.