IMPLICATIONS OF OBSERVATIONS OF VERY HIGH ENERGY GAMMA RAYS FROM PULSARS

Observations of gamma rays of energy greater than 3 × 1012 eV with a flux of 5 × 10-11 photons cm-2 s-1 from the pulsar CP 1133 have been reported by O'Mongain et al.1. In addition, Charman et al.2 reported a pulsed flux of 2 × 10-12 photons cm-2 s-1 above an energy 7 × 1013 eV. Fazio et al.3 do not observe gamma rays above 3 × 1012 eV from CP 1133 (or from some other pulsars), but their upper limits are consistent with the results of O'Mongain et al. Here I examine the ways in which these high energy photons can be produced and derive some implications from the observations. © 1969 Nature Publishing Group.