Pinning and Threading of Quantized Vortices in the Pulsar Crust Superfluid

Abstract

A neutron superfluid coexists with a lattice of nuclear clusters in the inner crust of a pulsar. Quantized vortices in this superfluid are pinned to the nuclear clusters in the innermost part of this region, while threading between nuclear clusters in outer layers. As a pulsar slows down, outer layers of the crust superfluid will be free to expel vortices while the pinning layer constrains the relaxation of the superfluid rotation throughout the crust and vortex movements through the core of the star. This picture should modify pulsar glitch models that depend on release of pinned vortices.