EVOLUTION OF GLOBULAR-CLUSTER PULSARS - PREDICTIONS

We predict the slowing-down rates, and hence magnetic fields, of globular cluster pulsars on the basis of statistical expectations. The key pulsars are the slower ones which must have strong magnetic fields to be detected at the distances of globular clusters. Since the characteristic age of such pulsars is small, they cannot have been formed at the same,time as the cluster. This short age in turn puts limits on the number of undetected pulsars in the cluster, because predecessors with similar magnetic fields would be expected but would now have slowed too much to be bright enough to be still detectable. One can estimate the period derivative directly from the period in such a statistical analysis (although determination of these derivatives is apparently complicated by acceleration within the cluster, at least in some cases). This analysis suggests that most of the pulsars created in globular clusters have substantial magnetic fields, ranging up to 10(12) G, and that the weak magnetic field ('millisecond') pulsars are formed comparatively rarely, but are disproportionately represented owing to their long lifetimes.