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Title: Formation and Eruption Process of a Filament in Active Region NOAA 12241

Abstract

In order to better understand active-region filaments, we present an intensive study on the formation and eruption of a filament in active region NOAA 12241 during the period from 2014 December 18 to 19. Using observations from the Helioseismic and Magnetic Imager (HMI) vector magnetograms, we investigate the helicity injection rate, Lorentz force, and vertical electric current in the entire region associated with the filament. The helicity injection rate before eruption is found to be larger than that after eruption, while the vertical electric current undergoes an increase at first and then a gradual decrease, similar to what the magnetic flux undergoes. Meanwhile, we find that the right part of the filament is formed by magnetic reconnection between two bundles of magnetic field lines while the left part originated from shearing motion. The interaction of the two parts causes the eruption of this filament. The mean horizontal magnetic fields in the vicinity of the magnetic polarity inversion line (PIL) enhance rapidly during the eruption. Another striking phenomenon, where the vertical electric currents close to the magnetic PIL suddenly expand toward two sides during the eruption, is found. We propose that this fascinating feature is associated with the release of energymore » during the eruption.« less

Authors:
; ; ; ;  [1]
  1. Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China)
Publication Date:
OSTI Identifier:
22663672
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 839; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; HELICITY; INJECTION; INTERACTIONS; LORENTZ FORCE; MAGNETIC FIELDS; MAGNETIC FLUX; MAGNETIC RECONNECTION; STAR EVOLUTION; STELLAR FLARES; SUN

Citation Formats

Wang, Jincheng, Yan, Xiaoli, Qu, ZhongQuan, Xue, Zhike, and Yang, Liheng. Formation and Eruption Process of a Filament in Active Region NOAA 12241. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA6BF3.
Wang, Jincheng, Yan, Xiaoli, Qu, ZhongQuan, Xue, Zhike, & Yang, Liheng. Formation and Eruption Process of a Filament in Active Region NOAA 12241. United States. doi:10.3847/1538-4357/AA6BF3.
Wang, Jincheng, Yan, Xiaoli, Qu, ZhongQuan, Xue, Zhike, and Yang, Liheng. Thu . "Formation and Eruption Process of a Filament in Active Region NOAA 12241". United States. doi:10.3847/1538-4357/AA6BF3.
@article{osti_22663672,
title = {Formation and Eruption Process of a Filament in Active Region NOAA 12241},
author = {Wang, Jincheng and Yan, Xiaoli and Qu, ZhongQuan and Xue, Zhike and Yang, Liheng},
abstractNote = {In order to better understand active-region filaments, we present an intensive study on the formation and eruption of a filament in active region NOAA 12241 during the period from 2014 December 18 to 19. Using observations from the Helioseismic and Magnetic Imager (HMI) vector magnetograms, we investigate the helicity injection rate, Lorentz force, and vertical electric current in the entire region associated with the filament. The helicity injection rate before eruption is found to be larger than that after eruption, while the vertical electric current undergoes an increase at first and then a gradual decrease, similar to what the magnetic flux undergoes. Meanwhile, we find that the right part of the filament is formed by magnetic reconnection between two bundles of magnetic field lines while the left part originated from shearing motion. The interaction of the two parts causes the eruption of this filament. The mean horizontal magnetic fields in the vicinity of the magnetic polarity inversion line (PIL) enhance rapidly during the eruption. Another striking phenomenon, where the vertical electric currents close to the magnetic PIL suddenly expand toward two sides during the eruption, is found. We propose that this fascinating feature is associated with the release of energy during the eruption.},
doi = {10.3847/1538-4357/AA6BF3},
journal = {Astrophysical Journal},
number = 2,
volume = 839,
place = {United States},
year = {Thu Apr 20 00:00:00 EDT 2017},
month = {Thu Apr 20 00:00:00 EDT 2017}
}
  • We investigate the formation, activation, and eruption of a flux rope (FR) from the sigmoid active region NOAA 11719 by analyzing E(UV), X-ray, and radio measurements. During the pre-eruption period of ∼7 hr, the AIA 94 Å images reveal the emergence of a coronal sigmoid through the interaction between two J-shaped bundles of loops, which proceeds with multiple episodes of coronal loop brightenings and significant variations in the magnetic flux through the photosphere. These observations imply that repetitive magnetic reconnections likely play a key role in the formation of the sigmoidal FR in the corona and also contribute toward sustaining themore » temperature of the FR higher than that of the ambient coronal structures. Notably, the formation of the sigmoid is associated with the fast morphological evolution of an S-shaped filament channel in the chromosphere. The sigmoid activates toward eruption with the ascent of a large FR in the corona, which is preceded by the decrease in photospheric magnetic flux through the core flaring region, suggesting tether-cutting reconnection as a possible triggering mechanism. The FR eruption results in a two-ribbon M6.5 flare with a prolonged rise phase of ∼21 minutes. The flare exhibits significant deviation from the standard flare model in the early rise phase, during which a pair of J-shaped flare ribbons form and apparently exhibit converging motions parallel to the polarity inversion line, which is further confirmed by the motions of hard X-ray footpoint sources. In the later stages, the flare follows the standard flare model and the source region undergoes a complete sigmoid-to-arcade transformation.« less
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