Observational Constraints on the Internal Structure and Dynamics of the Vela Pulsar

We show that the short spin-up time observed for the Vela pulsar during the1988 ``Christmas'' glitch implies that the coupling time of the pulsar core toits crust is less than $\sim$ 10 seconds. Ekman pumping cannot explain the fastcore-crust coupling and a more effective coupling is necessary. The internalmagnetic field of the Vela pulsar can provide the necessary coupling if thefield threads the core with a magnitude that exceeds $ 10^{13}$ Gauss for anormal interior and $ 10^{11}$ Gauss for a superconducting interior. Theselower bounds favor the hypothesis that the interior of neutron stars containssuperfluid neutrons and protons and challenge the notion that pulsar magneticfields decay over million year time scales or that magnetic flux is expelledfrom the core as the star slows.Comment: Latex with aasms4 style file, 15 pages, 1 ps figur