Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources

Nature, Published online: 17 May 2021; doi:10.1038/s41586-021-03498-z

Observations of γ-rays with energies up to 1.4 PeV find that 12 sources in the Galaxy are PeVatrons, one of which is the Crab Nebula.