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Title: IMPLOSION OF CORONAL LOOPS DURING THE IMPULSIVE PHASE OF A SOLAR FLARE

Abstract

We study the relationship between implosive motions in a solar flare, and the energy redistribution in the form of oscillatory structures and particle acceleration. The flare SOL2012-03-09T03:53 (M6.4) shows clear evidence for an irreversible (stepwise) coronal implosion. Extreme-ultraviolet (EUV) images show at least four groups of coronal loops at different heights overlying the flaring core undergoing fast contraction during the impulsive phase of the flare. These contractions start around a minute after the flare onset, and the rate of contraction is closely associated with the intensity of the hard X-ray and microwave emissions. They also seem to have a close relationship with the dimming associated with the formation of the coronal mass ejection and a global EUV wave. Several studies now have detected contracting motions in the corona during solar flares that can be interpreted as the implosion necessary to release energy. Our results confirm this, and tighten the association with the flare impulsive phase. We add to the phenomenology by noting the presence of oscillatory variations revealed by Geostationary Operational Environmental Satellite soft X-rays (SXR) and spatially integrated EUV emission at 94 and 335 Å. We identify pulsations of ≈60 s in SXR and EUV data, which we interpretmore » as persistent, semi-regular compressions of the flaring core region which modulate the plasma temperature and emission measure. The loop oscillations, observed over a large region, also allow us to provide rough estimates of the energy temporarily stored in the eigenmodes of the active-region structure as it approaches its new equilibrium.« less

Authors:
; ; ;  [1]
  1. SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)
Publication Date:
OSTI Identifier:
22270573
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 777; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCELERATION; ASTRONOMY; ASTROPHYSICS; ELECTRON TEMPERATURE; EXTREME ULTRAVIOLET RADIATION; GAMMA RADIATION; HARD X RADIATION; ION TEMPERATURE; MAGNETIC FIELDS; MICROWAVE RADIATION; OSCILLATIONS; SOFT X RADIATION; SOLAR CORONA; SOLAR FLARES; SUN

Citation Formats

Simões, P. J. A., Fletcher, L., Hudson, H. S., and Russell, A. J. B.,. IMPLOSION OF CORONAL LOOPS DURING THE IMPULSIVE PHASE OF A SOLAR FLARE. United States: N. p., 2013. Web. doi:10.1088/0004-637X/777/2/152.
Simões, P. J. A., Fletcher, L., Hudson, H. S., & Russell, A. J. B.,. IMPLOSION OF CORONAL LOOPS DURING THE IMPULSIVE PHASE OF A SOLAR FLARE. United States. https://doi.org/10.1088/0004-637X/777/2/152
Simões, P. J. A., Fletcher, L., Hudson, H. S., and Russell, A. J. B.,. 2013. "IMPLOSION OF CORONAL LOOPS DURING THE IMPULSIVE PHASE OF A SOLAR FLARE". United States. https://doi.org/10.1088/0004-637X/777/2/152.
@article{osti_22270573,
title = {IMPLOSION OF CORONAL LOOPS DURING THE IMPULSIVE PHASE OF A SOLAR FLARE},
author = {Simões, P. J. A. and Fletcher, L. and Hudson, H. S. and Russell, A. J. B.,},
abstractNote = {We study the relationship between implosive motions in a solar flare, and the energy redistribution in the form of oscillatory structures and particle acceleration. The flare SOL2012-03-09T03:53 (M6.4) shows clear evidence for an irreversible (stepwise) coronal implosion. Extreme-ultraviolet (EUV) images show at least four groups of coronal loops at different heights overlying the flaring core undergoing fast contraction during the impulsive phase of the flare. These contractions start around a minute after the flare onset, and the rate of contraction is closely associated with the intensity of the hard X-ray and microwave emissions. They also seem to have a close relationship with the dimming associated with the formation of the coronal mass ejection and a global EUV wave. Several studies now have detected contracting motions in the corona during solar flares that can be interpreted as the implosion necessary to release energy. Our results confirm this, and tighten the association with the flare impulsive phase. We add to the phenomenology by noting the presence of oscillatory variations revealed by Geostationary Operational Environmental Satellite soft X-rays (SXR) and spatially integrated EUV emission at 94 and 335 Å. We identify pulsations of ≈60 s in SXR and EUV data, which we interpret as persistent, semi-regular compressions of the flaring core region which modulate the plasma temperature and emission measure. The loop oscillations, observed over a large region, also allow us to provide rough estimates of the energy temporarily stored in the eigenmodes of the active-region structure as it approaches its new equilibrium.},
doi = {10.1088/0004-637X/777/2/152},
url = {https://www.osti.gov/biblio/22270573}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 777,
place = {United States},
year = {Sun Nov 10 00:00:00 EST 2013},
month = {Sun Nov 10 00:00:00 EST 2013}
}