Modelling the Magnetic Field Configuration of Neutron Stars

TL;DR

This paper reviews theoretical models of neutron star magnetic fields, emphasizing the stability of different configurations and recent developments like twisted-torus models, to better understand their evolution and observable phenomena.

Contribution

It provides a comprehensive overview of current modeling efforts, highlighting the instability of simple magnetic configurations and supporting the twisted-torus model as a promising solution.

Findings

Purely poloidal and toroidal fields are unstable in neutron stars.

Twisted-torus configurations are supported by recent evidence.

Theoretical models are crucial due to limited observational constraints.

Abstract

The properties of the extremely strong magnetic fields of neutron stars affect in a unique way their evolution and the associated phenomenology. Due to the lack of constraints from direct observations, our understanding of the magnetic field configuration in neutron star interiors depends on the progress in theoretical modelling. Here we discuss the effort in building models of magnetized neutron stars focussing on some of the recent results. In particular, we comment on the instability of purely poloidal and purely toroidal magnetic field configurations and on the evidence in favour of the so-called twisted-torus solutions. We conclude with an outlook on the present status of the field and future directions.