Accumulation and release of energy near the light cylinder of a neutron star

Abstract

We point out that high-energy particle bunches are produced by magnetic annihilation near the light cylinder and hence the pulsed radiation from a neutron star. More explicitly: (1) Magnetic energy may accumulate very rapidly owing to the differential rotation in the non-corotating region near the light cylinder of a neutron star. The scale of the accumulating region is consistent with the observed scale. (2) In a steady-state, the energy is released at the same rate as it is accumulated. We envisage the release to be accomplished by magnetic annihilation. The rate and scale of the high-energy bunches thus obtained agree with the observations. (3) The particle number density in the radiating region we found is much higher than that in the Goldreich-Julian model [1], and thus explaining the observed high density in the Crab pulsar pointed out in [2]. (4) Our model predicts that the γ-radiation and the radio radiation of a given neutron star may have different pulse periods.