Gamma-ray bursts from sheared alfvén waves in the magnetospheres of extragalactic radio pulsars

The distribution of gamma-ray bursts (GRBs) detected by BATSE, in combination with the spectral data gathered over the past two decades, argue for a cosmological population of neutron-star sources. We demonstrate that GRB spectra may be understood in the context of the Compton upscattering of typical radio pulsar spectra, providing a natural interpretation to the spectral break ∈ _break at ∼ 0.2-3 Mev often exhibited by GRBs. This model also predics a -γ-ray power spectral index -1 ≲ μ ≲ 2 above the break, though the prevalence of steeper radio spectra in the brightest pulsars implies a biasing of toward the bottom of this range. We find that the probability of detecting a burst in progress from any given source is ≈ 5 × 10 ^-11 , implying an individual stellar burst rate of about 1 every 50 years if all active pulsars are involved, or about 1 every 2 - 3 years for the very young members of this class. In addition, the energy released per burst coincides with those pertaining to the macro- and micro-glitches seen in the periods of many such sources. We conclude that GRBs may simply be the crustal adjustments responsible for the now familiar timing noise observed in young pulsars.