Pulsar Braking Index: A Test of Emission Models?

Abstract

Pulsar braking torques due to magnetodipole radiation and the unipolar generator are considered, which results in a braking index n of less than 3 and could be employed to test the emission models. Improved equations for the pulsar braking index and magnetic field are presented, which are true if the rotation energy-loss rate equals the sum of the energy-loss rate of dipole radiation and of relativistic particles powered by a unipolar generator. The magnetic field calculated conventionally could be good enough, but only if it were modified by a factor of at most ~0.6. Both inner and outer gaps may coexist in the magnetosphere of the Vela pulsar.