2011 FEBRUARY 15: SUNQUAKES PRODUCED BY FLUX ROPE ERUPTION

Journal Article · Thu Nov 10 04:00:00 EST 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/741/2/L35· OSTI ID:22047372

Zharkov, S; Green, L M; Matthews, S A ^[1]; Zharkova, V V ^[2]

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1. UCL Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking RH5 6NT (United Kingdom)
2. Department of Mathematics, University of Bradford, Bradford BD7 1DP (United Kingdom)

We present an analysis of the 2011 February 15 X-class solar flare, previously reported to produce the first sunquake in solar cycle 24. Using acoustic holography, we confirm the first, and report a second, weaker, seismic source associated with this flare. We find that the two sources are located at either end of a sigmoid, which indicates the presence of a flux rope. Contrary to the majority of previously reported sunquakes, the acoustic emission precedes the peak of major hard X-ray (HXR) sources by several minutes. Furthermore, the strongest HXR footpoints derived from RHESSI data are found to be located away from the seismic sources in the flare ribbons. We account for these discrepancies within the context of a phenomenological model of a flux rope eruption and accompanying two-ribbon flare. We propose that the sunquakes are triggered at the footpoints of the erupting flux rope at the start of the flare impulsive phase and eruption onset, while the main HXR sources appear later at the footpoints of the flare loops formed under the rising flux rope. Possible implications of this scenario for the theoretical interpretation of the forces driving sunquakes are discussed.

• OSTI ID: 22047372
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 741; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTROPHYSICS
COSMIC X-RAY SOURCES
ERUPTION
GAMMA RADIATION
HARD X RADIATION
MASS
SEISMIC SOURCES
SOLAR CYCLE
SOLAR FLARES
SUN
SUNSPOTS