Evolution of pulsar magnetic fields

Abstract

Theoretical considerations of neutron star matter and magnetic fields suggest a picture of the evolution of pulsar dipole moments. At birth the spin axis and magnetic dipole are argued to be roughly aligned. Subsequently the magnetic dipole greatly diminishes in strength and changes its direction until it ultimately makes a large angle with the spin axis. This view is supported by observations of pulsar subpulse drifting and the relation of pulsar periods to spin-down rates.