Pulsar constraints on neutron star structure and equation of state

With the aim of constraining the structural properties of neutron stars and the equation of state of dense matter, we study sudden spin-ups, glitches, occurring in the Vela pulsar and in six other pulsars. We present evidence that glitches represent a self-regulating instability for which the star p repares over a waiting time. The angular momentum requirements of glitches in Vela indicate that greater than or equal to 1.4% Of the star's moment of inertia drives these events. If glitches originate in the liquid of the in ner crust, Vela's "radiation radius" R-infinity must exceed similar or equa l to 12 km for a mass of 1.4M(.). Observational tests of whether other neut ron stars obey this constraint will be possible in the near future.