The pulsar timing noise component produced by a variable internal torque is a source of information about the neutron superfluid rotation. It is shown that the existence of a region in which the vortices corotate with the superfluid explains the properties of the discrete micro-events identified by Cordes & Downs and allows the formulation of a noise model for the rotation angular velocity time-derivative not inconsistent with the measured power spectra of PSR 0531+21 and 0833-45. The model provides some indication that the millisecond pulsar 1937+21 is anomalously quiet: a possible explanation is that it lacks a neutron-drip superfluid owing to the presence of an absolutely stable quark matter phase.
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- September 1990