Origin and evolution of neutron star magnetic fields

TL;DR

This paper reviews current understanding of neutron star magnetic fields, their origins, and evolution, highlighting observational challenges and discussing possible progenitor links and physical processes influencing magnetic field changes.

Contribution

It provides a comprehensive overview of neutron star magnetic phenomenology, discusses observational limitations, and explores theories on the origin and evolution of their magnetic fields.

Findings

Magnetic fields in neutron stars range from 10^8 to 10^15 G.

Observational determinations of field strength are limited and evolving.

Possible main-sequence origins of neutron star magnetic fields are discussed.

Abstract

This paper intends to give a broad overview of the present knowledge about neutron star magnetic fields, their origin and evolution. An up-to-date overview of the rich phenomenology (encompassing ``classical'' and millisecond radio pulsars, X-ray binaries, ``magnetars'', and ``thermal emitters'') suggests that magnetic fields on neutron stars span at least the range $10^{8-15}$ G, corresponding to a range of magnetic fluxes similar to that found in white dwarfs and upper main sequence stars. The limitations of the observational determinations of the field strength and evidence for its evolution are discussed. Speculative ideas about the possible main-sequence origin of the field (``magnetic strip-tease'') are presented. Attention is also given to physical processes potentially leading to magnetic field evolution.