Dynamical Oscillations and Glitches in AXPs

TL;DR

This paper proposes that magnetar glitches and associated X-ray brightening events are caused by deep energy releases triggering global mechanical motion, leading to crustal oscillations and short flares, with implications for understanding magnetar behavior.

Contribution

It introduces a new model linking magnetar glitches to deep energy releases and mechanical unpinning, explaining observed correlations and predicting short flares.

Findings

Glitches are accompanied by X-ray brightening events.

Deep energy releases below 100 meters trigger mechanical unpinning.

Crustal oscillations may cause short, intense flares.

Abstract

Recently reported observations of magnetar glitches and coincident X-ray long term brightening events establish enough of a data base to indicate that the brightening events are accompanied by glitches at their outset, and that they are probably triggered by the same event that triggers the glitch. We suggest, on the basis of various observational clues, that a) these are caused by energy releases at depths below 100 meters, and b) the unpinning is due to global mechanical motion triggered by the energy release, not by heat. Because mechanical triggering of a glitch requires less energy than a detectable long term X-ray brightening, the latter does not necessarily accompany every glitch, but it is predicted, when it does occur, to be heralded by a glitch. Crustal oscillation associated with the mechanical energy release may cause short ($\ll 10^3$s) flares.