Non-equilibrium Flux Rope Formation by Confined Flares Preceding a Solar Coronal Mass Ejection

Abstract

We present evidence that a magnetic flux rope was formed before a coronal mass ejection (CME) and its associated long-duration flare during a pair of preceding confined eruptions and associated impulsive flares in a compound event in NOAA Active Region 12371. Extreme-ultraviolet images and the extrapolated nonlinear force-free field show that the first two, impulsive flares, SOL2015-06-21T01:42, result from the confined eruption of highly sheared low-lying flux, presumably a seed flux rope. The eruption spawns a vertical current sheet, where magnetic reconnection creates flare ribbons and loops, a nonthermal microwave source, and a sigmoidal hot channel which can only be interpreted as a magnetic flux rope. Until the subsequent long-duration flare, SOL2015-06-21T02:36, the sigmoid's elbows expand, while its center remains stationary, suggesting non-equilibrium but not yet instability. The "flare reconnection" during the confined eruptions acts like "tether-cutting reconnection" whose flux feeding of the rope leads to instability. The subsequent full eruption is seen as an accelerated rise of the entire hot channel, seamlessly evolving into the fast halo CME. Both the confined and ejective eruptions are consistent with the onset of the torus instability in the dipped decay index profile which results from the region's two-scale magnetic structure. We suggest that the formation or enhancement of a non-equilibrium but stable flux rope by confined eruptions is a generic process occurring prior to many CMEs.

Accepted by the ApJ; v1: initial submission

References in corpus (29)

• Torus instability
• Optimization code with weighting function for the reconstruction of coronal magnetic fields
• Preprocessing of vector magnetograph data for a non-linear force-free magnetic field reconstruction
• Observation of An Evolving Magnetic Flux Rope Prior To and During A Solar Eruption
• Photospheric flux cancellation and associated flux rope formation and eruption
• Numerical simulations of fast and slow coronal mass ejections
• Three-Dimensional MHD Simulation of the 2003 October 28 Coronal Mass Ejection: Comparison with LASCO Coronagraph Observations
• Slow Rise and Partial Eruption of a Double-Decker Filament. I Observations and Interpretation
• Sigmoid-to-Flux-Rope Transition Leading to A Loop-Like Coronal Mass Ejection
• Decoding the Pre-Eruptive Magnetic Field Configurations of Coronal Mass Ejections
• Flux Rope Formation Preceding Coronal Mass Ejection Onset
• High-resolution observations of flare precursors in the low solar atmosphere
• Initiation and Early Kinematic Evolution of Solar Eruptions
• Chromosphere to 1 AU Simulation of the 2011 March 7th Event: A Comprehensive Study of Coronal Mass Ejection Propagation
• Origins of Rolling, Twisting and Non-Radial Propagation of Eruptive Solar Events
• Slow Rise and Partial Eruption of a Double-Decker Filament. II. Modeling by a Double Flux Rope Equilibrium
• Imaging and Spectroscopic Diagnostics on the Formation of Two Magnetic Flux Ropes Revealed by SDO/AIA and IRIS
• Double arc instability in the solar corona
• Critical Height of the Torus Instability in Two-Ribbon Solar Flares
• Formation and eruption of a flux rope from the sigmoid active region NOAA 11719 and associated M6.5 flare: A multi-wavelength study
• Direct Evidence of an Eruptive, Filament-Hosting Magnetic Flux Rope Leading to a Fast Solar Coronal Mass Ejection
• A Prominence Eruption Driven by Flux Feeding from Chromospheric Fibrils
• Successive Homologous Coronal Mass Ejections driven by shearing and converging motions in solar active region NOAA 12371
• Witnessing a Large-scale Slipping Magnetic Reconnection along a Dimming Channel during a Solar Flare
• When do solar erupting hot magnetic flux ropes form?
• HXR emission from an activated flux rope and subsequent evolution of an eruptive long duration solar flare
• Eruption of Solar Magnetic Flux Ropes Caused by Flux Feeding
• A new trigger mechanism for coronal mass ejections: the role of confined flares and photospheric motions in the formation of hot flux ropes
• The 17 February 2013 sunquake in the context of the active region's magnetic field configuration

Cited by in corpus (13)

• Decoding the Pre-Eruptive Magnetic Field Configurations of Coronal Mass Ejections
• The Sun and Space Weather
• Torus-Stable Zone Above Starspots
• Toward a Unified Explanation for the Three-part Structure of Solar Coronal Mass Ejections
• Partial Eruption, Confinement, and Twist Buildup and Release of a Double-decker Filament
• A Model of Homologous Confined and Ejective Eruptions Involving Kink Instability and Flux Cancellation
• A Data-constrained Magnetohydrodynamic Simulation of the X1.0 Solar Flare of 2021 October 28
• The Structure of Coronal Mass Ejections Recorded by the K-Coronagraph at Mauna Loa Solar Observatory
• A Comparative Study of Solar Active Region 12371 with Data-constrained and Data-driven MHD Simulations
• Where and how does a decay-index profile become saddle-like?
• Thermodynamic evolution of a sigmoidal active region with associated flares
• Global energetics of solar powerful events on 6 September 2017
• The Kinematical Behavior of Solar Eruptive Filaments Affected by the Poloidal Magnetic Field