Magnetars: Properties, Origin and Evolution

TL;DR

Magnetars are neutron stars with extremely strong magnetic fields, exhibiting variable X-ray emissions and complex magnetic structures, with recent studies advancing understanding of their origins and evolution.

Contribution

This paper reviews observed properties, discusses models for magnetic field origins, and presents recent developments in magnetar evolution and their relation to other neutron stars.

Findings

Magnetars have magnetic fields of 10^{13-15} G.

They exhibit variable X-ray and radio emissions.

Recent models explain their magnetic field origins and evolution.

Abstract

Magnetars are neutron stars in which a strong magnetic field is the main energy source. About two dozens of magnetars, plus several candidates, are currently known in our Galaxy and in the Magellanic Clouds. They appear as highly variable X-ray sources and, in some cases, also as radio and/or optical pulsars. Their spin periods (2-12 s) and spin-down rates (~10^{-13}-10^{-10} s/s) indicate external dipole fields of ~10^{13-15} G, and there is evidence that even stronger magnetic fields are present inside the star and in non-dipolar magnetospheric components. Here we review the observed properties of the persistent emission from magnetars, discuss the main models proposed to explain the origin of their magnetic field and present recent developments in the study of their evolution and connection with other classes of neutron stars.