Powerful flares and magneto-elastic oscillations of magnetars

TL;DR

This paper explores the connection between powerful magnetar flares, their associated quasi-periodic oscillations, and the underlying magnetic and elastic properties of neutron stars, highlighting current theoretical gaps.

Contribution

It reviews the current understanding of magnetar flares and QPOs, emphasizing the need for improved theories to interpret observed phenomena.

Findings

Magnetar flares are linked to superstrong magnetic fields exceeding 10^15 G.

QPOs observed after flares are interpreted as stellar vibrations.

Current theories are incomplete in explaining magnetar flare mechanisms.

Abstract

Magnetars are neutron stars with superstrong magnetic fields which can exceed 1e15 G. Some magnetars (the so-called soft gamma-repeaters) demonstrate occasionally very powerful processes of energy release, which result in exceptionally strong flares of electromagnetic radiation. It is believed that these flares are associated with the presence of superstrong magnetic fields. Despite many hypotheses, the mechanism of these flares remains a mystery. In afterglows of the flares, one has often observed quasi-periodic oscillations (QPOs) of magnetar emission. They are interpreted as stellar vibrations, excited by the flares, which are useful for exploring the nature of magnetar activity. The incompleteness of theories employed to interpret magnetar QPOs is discussed.