EVOLUTION OF HARD X-RAY SOURCES AND ULTRAVIOLET SOLAR FLARE RIBBONS FOR A CONFINED ERUPTION OF A MAGNETIC FLUX ROPE

Journal Article · Fri Feb 10 04:00:00 EST 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/746/1/17· OSTI ID:22011838

Guo, Y; Ding, M D ^[1]; Schmieder, B; Demoulin, P ^[2]; Li, H ^[3]

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1. Department of Astronomy, Nanjing University, Nanjing 210093 (China)
2. LESIA, Observatoire de Paris, CNRS, UPMC, Universite Paris Diderot, F-92190 Meudon (France)
3. Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

We study the magnetic field structures of hard X-ray (HXR) sources and flare ribbons of the M1.1 flare in active region NOAA 10767 on 2005 May 27. We have found in a nonlinear force-free field extrapolation over the same polarity inversion line, a small pre-eruptive magnetic flux rope located next to sheared magnetic arcades. RHESSI and the Transition Region and Coronal Explorer (TRACE) observed this confined flare in the X-ray bands and ultraviolet (UV) 1600 A bands, respectively. In this event magnetic reconnection occurred at several locations. It first started at the location of the pre-eruptive flux rope. Then, the observations indicate that magnetic reconnection occurred between the pre-eruptive magnetic flux rope and the sheared magnetic arcades more than 10 minutes before the flare peak. This implies the formation of the larger flux rope, as observed with TRACE. Next, HXR sources appeared at the footpoints of this larger flux rope at the peak of the flare. The associated high-energy particles may have been accelerated below the flux rope in or around a reconnection region. Still, the close spatial association between the HXR sources and the flux rope footpoints favors an acceleration within the flux rope. Finally, a topological analysis of a large solar region, including active regions NOAA 10766 and 10767, shows the existence of large-scale Quasi-Separatrix Layers (QSLs) before the eruption of the flux rope. No enhanced emission was found at these QSLs during the flare, but the UV flare ribbons stopped at the border of the closest large-scale QSL.

• OSTI ID: 22011838
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 746; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCELERATION
ERUPTION
GAMMA RADIATION
HARD X RADIATION
MAGNETIC FIELDS
MAGNETIC FLUX
MAGNETIC RECONNECTION
NONLINEAR PROBLEMS
PHOTON EMISSION
SOLAR FLARES
SOLAR SYSTEM EVOLUTION
STAR EVOLUTION
SUN
ULTRAVIOLET RADIATION