Generating neutron-star magnetic fields: three dynamo phases

TL;DR

This paper proposes a new precession-driven dynamo mechanism for neutron star magnetic field generation, challenging traditional dynamo models and suggesting broader applicability to main-sequence stars.

Contribution

It introduces a novel precession-driven dynamo model and advocates for a revised mean-field approach to neutron star magnetic field generation.

Findings

Traditional dynamo models are insufficient for the strongest neutron star fields.

Precession-driven dynamo can generate magnetic fields in neutron stars.

Potential role of precession-driven dynamo in main-sequence stars.

Abstract

Young neutron stars (NSs) have magnetic fields $B$ in the range $10^{12}-10^{15}$ G, believed to be generated by dynamo action at birth. We argue that such a dynamo is actually too inefficient to explain the strongest of these fields. Dynamo action in the mature star is also unlikely. Instead we propose a promising new precession-driven dynamo and examine its basic properties, as well as arguing for a revised mean-field approach to NS dynamos. The precession-driven dynamo could also play a role in field generation in main-sequence stars.