Thermo-Resistive Instability in Magnetar Crusts

TL;DR

This paper explores a thermo-resistive instability in magnetar crusts, showing that certain conditions can lead to rapid thermal and magnetic changes, potentially explaining magnetar bursting activity.

Contribution

It identifies conditions under which thermo-resistive instability occurs in magnetar crusts and discusses its implications for magnetar evolution and activity.

Findings

Magnetar crusts are unstable over days if strong current sheets are present.

The instability affects thermal and magnetic evolution of magnetars.

Potential link to magnetar bursting activity.

Abstract

We investigate a thermo-resistive instability in the outer crusts of magnetars wherein a perturbation in temperature increases ohmic heating. We show that magnetars of characteristic age {\tau}_{age} ~ 10^4 yr are unstable over timescales as short as days if strong current sheets are present in the outer crust. This instability could play an important role in the thermal and magnetic field evolution of magnetars, and may be related to bursting activity in magnetars.