Finding the critical decay index in solar prominence eruptions
arXiv:1909.10442 · doi:10.3847/1538-4357/ab4793
Abstract
The background field is assumed to play prime role in the erupting structures like prominences. In the flux rope models, the critical decay index () is a measure of the rate at which background field intensity decreases with height over the flux rope or erupting structure. In the real observations, the critical height of the background field is unknown, so a typical value of is adopted from the numerical studies. In this study, we determined the of 10 prominence eruptions (PEs). The prominence height in 3D is derived from two-perspective observations of \textit{Solar Dynamics Observatory} and \textit{Solar TErrestrial RElations Observatory}. Synoptic maps of photospheric radial magnetic field are used to construct the background field in the corona. During the eruption, the height-time curve of the sample events exhibits the slow and fast-rise phases and is fitted with the linear-cum-exponential model. From this model, the onset height of fast-rise motion is determined and is considered as the critical height for the onset of the torus-instability because the erupting structure is allowed to expand exponentially provided there is no strapping background field. Corresponding to the critical height, the values of our sample events are varied to be in the range of 0.8-1.3. Additionally, the kinematic analysis suggests that the acceleration of PEs associated with flares are significantly enhanced compared to flare-less PEs. We found that the flare magnetic reconnection is the dominant contributor than the torus-instability to the acceleration process during the fast-rise phase of flare-associated PEs in low corona ().
12 pages, 6 figures and 2 tables
References in corpus (22)
- Torus instability
- Confined and ejective eruptions of kink-unstable flux ropes
- Criteria for Flux Rope Eruption: Non Equilibrium versus Torus Instability
- Combined STEREO/RHESSI study of CME acceleration and particle acceleration in solar flares
- Numerical simulations of fast and slow coronal mass ejections
- Prominence and Filament Eruptions Observed by the Solar Dynamics Observatory: Statistical Properties, Kinematics, and Online Catalog
- The Driver of Coronal Mass Ejections in the Low Corona: A Flux Rope
- Critical decay index at the onset of solar eruptions
- A Comparative Study of Confined and Eruptive Flares in NOAA AR 10720
- Investigating Two Successive Flux Rope Eruptions In A Solar Active Region
- Statistical Analysis of Torus and Kink Instabilities in Solar Eruptions
- Why torus-unstable solar filaments experience failed eruption?
- Catastrophic eruption of magnetic flux rope in the corona and solar wind with and without magnetic reconnection
- Filament eruption on 2010 October 21 from three viewpoints
- Near-Sun Flux Rope Structure of CMEs
- Statistical study of magnetic non-potential measures in confined and eruptive flares
- A Study of Fast Flareless Coronal Mass Ejections
- Initiation and Eruption Process of Magnetic Flux Rope from Solar Active Region NOAA 11719 to Earth Directed-CME
- Acceleration phases of a solar filament during its eruption
- Study of Three-Dimensional Magnetic Structure and the Successive Eruptive Nature of Active Region 12371
- Prominence eruption initiated by helical kink-instability of an embedded flux rope
- Two Energy Release Processes for CMEs: MHD Catastrophe and Magnetic Reconnection