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

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) i...

Full description

Saved in:
Bibliographic Details
Published in:The Astrophysical journal 2013-11, Vol.777 (2), p.1-9
Main Authors: Simoes, P J A, Fletcher, L, Hudson, H S, Russell, A J B
Format: Article
Language:English
Subjects:
ACCELERATION
ASTRONOMY
ASTROPHYSICS
ASTROPHYSICS, COSMOLOGY AND ASTRONOMY
Coronal loops
Coronas
ELECTRON TEMPERATURE
Emission
EXTREME ULTRAVIOLET RADIATION
Flares
GAMMA RADIATION
HARD X RADIATION
Implosions
ION TEMPERATURE
MAGNETIC FIELDS
MICROWAVE RADIATION
OSCILLATIONS
Particle acceleration
SOFT X RADIATION
Soft x-rays
SOLAR CORONA
SOLAR FLARES
SUN
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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 A. We identify pulsations of approximately 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.
ISSN:0004-637X
1538-4357
DOI:10.1088/0004-637X/777/2/152