Solar Magnetic Flux Ropes

Abstract

The most probable initial magnetic configuration of a CME is a flux rope consisting of twisted field lines which fill the whole volume of a dark coronal cavity. The flux ropes can be in stable equilibrium in the coronal magnetic field for weeks and even months, but suddenly they loose their stability and erupt with high speed. Their transition to the unstable phase depends on the parameters of the flux rope (i.e., total electric current, twist, mass loading etc.), as well as on the properties of the ambient coronal magnetic field. One of the major governing factors is the vertical gradient of the coronal magnetic field which is estimated as decay index (n). Cold dense prominence material can be collected in the lower parts of the helical flux tubes. Filaments are therefore good tracers of the flux ropes in the corona, which become visible long before the beginning of the eruption. The perspectives of the filament eruptions and following CMEs can be estimated by the comparison of observed filament heights with calculated decay index distributions. The present paper reviews the formation of magnetic flux ropes, their stable and unstable phases, eruption conditions, and also discusses their physical implications in the solar corona.

27 pages, 14 figures; to appear in Journal of Astrophysics & Astronomy (Special Issue; Eds: V. Fedun, A.K. Srivastava, R. Erdelyi, J.C. Pandey)

References in corpus (10)

• Torus instability
• Formation of current sheets and sigmoidal structure by the kink instability of a magnetic loop
• Emergence of a Helical Flux Rope Under an Active Region Prominence
• Catastrophe versus instability for the eruption of a toroidal solar magnetic flux rope
• Current amplification and magnetic reconnection at a 3D null point. I - Physical characteristics
• Current sheet formation and non-ideal behaviour at three-dimensional magnetic null points
• On the Relationship Between a Hot-channel-like Solar Magnetic Flux Rope and its embedded Prominence
• A Reconnecting Current Sheet Imaged in A Solar Flare
• Analysis and interpretation of a fast limb CME with eruptive prominence, C-flare and EUV dimming
• Fast Magnetic Twister and Plasma Perturbations in a 3-D Coronal Arcade

Cited by in corpus (7)

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• HXR emission from an activated flux rope and subsequent evolution of an eruptive long duration solar flare
• Evolution of the Non-potential Magnetic Field in the Solar Active Region 12673 Based on a Nonlinear Force-free Modeling
• Sequential Lid Removal in a Triple-Decker Chain of CME-Producing Solar Eruptions
• Radiative Magnetohydrodynamic Simulation of the Confined Eruption of a Magnetic Flux Rope: Magnetic Structure and Plasma Thermodynamics
• Interplanetary magnetic flux rope observed at ground level by HAWC
• Mysterious High Energy Gamma Rays Might Help Explain What Drives Solar Cycles