POPULATION SYNTHESIS OF MILLISECOND AND SUBMILLISECOND PULSARS

Known millisecond pulsars have periods longer than 1.558 ms. Recycled in binary systems, neutron stars can attain very short spin periods. I n this Letter, we investigate the expected properties of the milliseco nd pulsar distribution by simulating synthetic populations under diffe rent assumptions for the neutron star equation of state and the decay of the magnetic field. We find evidence that a tail in the distributio n of millisecond pulsars may exist at periods shorter than those obser ved.