Nature of pulsar gamma rays

The generation of ..gamma.. rays due to the curvature of the magnetic field lines and their escape from the neighborhood of a pulsar are discussed. With allowance for the production by ..gamma..-ray photons of electron-positron pairs in a strong magnetic field, the distance at which the ..gamma.. rays begin freely to leave the pulsar neighborhood is determined. Estimates are obtained for the power of the ..gamma.. rays and the frequency of the emission maximum. The values obtained are in reasonable accord with the observed ..gamma..-ray parameters for both young pulsars (NP 0532, PSR 0833-45) and relatively old ones (PSR 1747-46, PSR 1818-04). In general the directional pattern of pulsar ..gamma.. rays will not coincide with the radio beam. This circumstance may explain the phase shift of the ..gamma..-ray pulses relative to the radio pulses observed in three of the four ..gamma..-ray pulsars known prior to 1977, as well as the fact that ..gamma.. rays have thus far been observed for only two old pulsars. The model developed here predicts that ..gamma..-ray pulsars without appreciable radio emission should exist; many of them could be members of binary systems.