A rotationally-powered magnetar nebula around Swift J1834.9-0846

TL;DR

This paper demonstrates that the extended X-ray nebula around the magnetar Swift J1834.9-0846 can be explained as a rotationally-powered pulsar wind nebula, with environmental compression and reverberation effects accounting for its unique detection.

Contribution

It provides a detailed model showing the nebula's sustainability without extra energy sources, highlighting environmental effects like reverberation as key factors.

Findings

The nebula can be explained as rotationally-powered.

Reverberation effects are crucial for nebula detection.

Estimated age of the magnetar based on nebula dynamics.

Abstract

A wind nebula, generating extended X-ray emission, was recently detected surrounding Swift J1834.9-0846. This is the first magnetar for which such a wind nebula was found. Here, we investigate whether there is a plausible scenario where the pulsar wind nebula (PWN) can be sustained without the need of advocating for additional sources of energy other than rotational. We do this by using a detailed radiative and dynamical code that studies the evolution of the nebula and its particle population in time. We find that such a scenario indeed exists: Swift J1834.9-0846's nebula can be explained as being rotationally-powered, as all other known PWNe are, if it is currently being compressed by the environment. The latter introduces several effects, the most important of which is the appearance of adiabatic heating, being increasingly dominant over the escape of particles as reverberation goes by. The need of reverberation naturally explains why this is the only magnetar nebula detected, and provides estimates for Swift 1834.9-0846's age.