Solar-type Magnetic Reconnection Model for Magnetar Giant Flare

TL;DR

This paper proposes a theoretical model for magnetar giant flares based on solar flare physics, emphasizing the role of preflare activity, baryonic matter loading, and magnetic reconnection in producing these energetic events.

Contribution

It introduces a novel magnetar flare model that incorporates baryonic matter loading and magnetic reconnection, differing from solar flares by the dominance of radiative control processes.

Findings

Explains the physical properties of the 2004 giant flare from SGR1806-20.

Accounts for baryonic matter in the ejecta of magnetar flares.

Highlights the role of magnetic reconnection in triggering giant flares.

Abstract

We present a theoretical model describing magnetar giant flares on the basis of solar flare/coronal mass ejection theory. In our model, a preflare activity plays a crucial role in driving evaporating flows and supplying baryonic matters into the magnetosphere. The loaded baryonic matter, that is called "prominence", is then gradually uplifted via crustal cracking with maintaining a quasi-force-free equilibrium of the magnetosphere. Finally the prominence is erupted by the magnetic pressure force due to the loss of equilibrium triggered by the explosive magnetic reconnection. The giant flare should be induced as a final outcome of the prominence eruption accompanied by large-scale field reconfigurations. An essential difference between solar and magnetar flares is the control process of their evolutionary dynamics. The flaring activity on magnetars is mainly controlled by the radiative process unlike the solar flare governed by the electron conduction. It is highly suggestive that our model is accountable for the physical properties of the extraordinary giant flare observed on 2004 December 27 from SGR1806-20, including the source of baryonic matters loaded in the expanding ejecta observed after the giant burst.