Helioseismic analysis of the solar flare-induced sunquake of 2005 January 15

Hamed Moradi, Alina-Catalina Donea, Charles Allan Lindsey, Diana Besliu-Ionescu, Paul Stuart Cally

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We report the discovery of one of the most powerful sunquakes detected to date, produced by an X1.2-class solar flare in active region AR10720 on 2005 January 15. We used helioseismic holography to image the source of seismic waves emitted into the solar interior from the site of the flare. Acoustic egression power maps at 3 and 6 mHz with a 2-mHz bandpass reveal a compact acoustic source strongly correlated with impulsive hard X-ray and visible-continuum emission along the penumbral neutral line separating the two major opposing umbrae in the delta-configuration sunspot that predominates AR10720. At 6 mHz the seismic source has two components, an intense, compact kernel located on the penumbral neutral line of the delta-configuration sunspot that predominates AR10720, and a significantly more diffuse signature distributed along the neutral line up to similar to 15 Mm east and similar to 30 Mm west of the kernel. The acoustic emission signatures were directly aligned with both hard X-ray and visible continuum emission that emanated during the flare. The visible continuum emission is estimated at 2.0 x 10(23) J, approximately 500 times the seismic emission of similar to 4 x 10(20) J. The flare of 2005 January 15 exhibits the same close spatial alignment between the sources of the seismic emission and impulsive visible continuum emission as previous flares, reinforcing the hypothesis that the acoustic emission may be driven by heating of the low photosphere. However, it is a major exception in that there was no signature to indicate the inclusion of protons in the particle beams thought to supply the energy radiated by the flare. The continued strong coincidence between the sources of seismic emission and impulsive visible continuum emission in the case of a proton-deficient white-lightflare lends substantial support to the back-warming hypothesis, that the low photosphere is significantly heated by intense Balmer and Paschen continuum-edge radiation from the overly
Original languageEnglish
Pages (from-to)1155 - 1163
Number of pages9
JournalMonthly Notices of the Royal Astronomical Society: Letters
Issue number3
Publication statusPublished - 2007

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