Pulsar braking: magnetodipole vs. wind

TL;DR

This paper argues that pulsar spin-down is better explained by wind braking involving the magnetosphere rather than the traditional vacuum magnetic dipole model, supported by recent observations.

Contribution

It introduces the wind braking model as a more accurate paradigm for pulsar spin-down, challenging the long-standing vacuum dipole assumption.

Findings

Magnetic dipole braking in vacuum is inconsistent with observations.

The wind braking model explains pulsar and magnetar data coherently.

A fallback disk model is also discussed as an alternative.

Abstract

Pulsars are good clocks in the universe. One fundamental question is that why they are good clocks? This is related to the braking mechanism of pulsars. Nowadays pulsar timing is done with unprecedented accuracy. More pulsars have braking indices measured. The period derivative of intermittent pulsars and magnetars can vary by a factor of several. However, during pulsar studies, the magnetic dipole braking in vacuum is still often assumed. It is shown that the fundamental assumption of magnetic dipole braking (vacuum condition) does not exist and it is not consistent with the observations. The physical torque must consider the presence of the pulsar magnetosphere. Among various efforts, the wind braking model can explain many observations of pulsars and magnetars in a unified way. It is also consistent with the up-to-date observations. It is time for a paradigm shift in pulsar studies: from magnetic dipole braking to wind braking. As one alternative to the magnetospheric model, the fallback disk model is also discussed.