GAMMA-RAY BURSTS FROM EXTINCT NEUTRON-STARS

In the Michel-Dessler theory of pulsars, pulsar action is stimulated by the presence of a fossil Kepler disk. Pulsar extinction occurs when this disk is pushed beyond the corotation distance. Once pulsar action ceases, a thin disk will very slowly expand away from this very dense reservoir under internal viscous forces. When the inner edge approaches sufficiently close to the star, a runaway ionization instability that will cause this thin disk to become fully ionized and be precipitated onto the neutron star surface. Quite nominal estimates suggest that energies of 10(39) ergs or more could be released with rise times as fast as 0.3 milliseconds. Because every extinct pulsar would be surrounded by such a disk, there should be a large number of such objects and we estimate that pulses could be produced at the rate of several a month from the nearby (few hundred parsecs) spherically distributed population of the otherwise inactive neutron stars. The mass of the reservoir (estimated to be about 10(-5) M.) would be adequate to supply one burst/year over the age of the universe. Our rough estimate, however, is that each source bursts only once in about 10(5) years. These numbers seem broadly consistent with observed properties of gamma-ray bursters.