Multiwavelength Observations of an Eruptive Flare: Evidence for Blast Waves and Break-out

TL;DR

This study presents multiwavelength observations of a solar eruptive flare, providing evidence for blast waves and flux rope break-out, and discusses the dynamics of the eruption and associated wave phenomena.

Contribution

It offers new observational evidence supporting the roles of blast waves and flux rope break-out in solar eruptions, contrasting with standard reconnection models.

Findings

Detection of high-velocity waves (>1000 km/s) during the eruption

Correlation between waves and type-II radio emissions

Observation of cavity collapse and hot loop formation

Abstract

Images of an east-limb flare on 3 November 2010 taken in the 131 \AA\ channel of the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory provide a convincing example of a long current sheet below an erupting plasmoid, as predicted by the standard magnetic reconnection model of eruptive flares. However, the 171 \AA\ and 193 \AA\ channel images hint at an alternative scenario. These images reveal that large-scale waves with velocity greater than 1000 km/s propagated alongside and ahead of the erupting plasmoid. Just south of the plasmoid, the waves coincided with type-II radio emission, and to the north, where the waves propagated along plume-like structures, there was increased decimetric emission. Initially the cavity around the hot plasmoid expanded. Later, when the erupting plasmoid reached the height of an overlying arcade system, the plasmoid structure changed, and the lower parts of the cavity collapsed inwards. Hot loops appeared alongside and below the erupting plasmoid. We consider a scenario in which the fast waves and the type-II emission were a consequence of a flare blast wave, and the cavity collapse and the hot loops resulted from the break-out of the flux rope through an overlying coronal arcade.