Quasi-Periodic Oscillations in magnetars: linking variability and emission

TL;DR

This paper investigates the nature of quasi-periodic oscillations in magnetars, showing they are likely produced by an additional emission process rather than direct seismic oscillations, based on recent observational analysis.

Contribution

It challenges the interpretation of QPOs as direct seismic signals, proposing an alternative emission mechanism based on observational evidence.

Findings

QPO amplitude remains nearly constant across rotation phases.

Global seismic oscillations are not directly observable in the lightcurve.

QPOs may originate from an additional emission process.

Abstract

I present recent results studying flare emission in magnetars. Strong quasi-periodic oscillations observed in the tail of giant magnetar flares are frequently interpreted as evidence for global seismic oscillations. I demonstrate that such a global oscillation is not directly observable in the lightcurve. New work suggests the amplitude for the strongest QPO stays nearly constant in the rotation phases where it is observed, which I argue suggests it is produced by an additional emission process from the star.