Abstract
An X17 class (GOES soft X-ray) two-ribbon solar flare on October 28, 2003 is analyzed in order to determine the relationship between the timing of the impulsive phase of the flare and the magnetic shear change in the flaring region. EUV observations made by the Transition Region and Coronal Explorer (TRACE) show a clear decrease in the shear of the flare footpoints during the flare. The shear change stopped in the middle of the impulsive phase. The observations are interpreted in terms of the splitting of the sheared envelope field of the greatly sheared core rope during the early phase of the flare. We have also investigated the temporal correlation between the EUV emission from the brightenings observed by TRACE and the hard X-ray (HXR) emission (E > 150 keV) observed by the anticoincidence system (ACS) of the spectrometer SPI on board the ESA INTEGRAL satellite. The correlation between these two emissions is very good, and the HXR sources (RHESSI) late in the flare are located within the two EUV ribbons. These observations are favorable to the explanation that the EUV brightenings mainly result from direct bombardment of the atmosphere by the energetic particles accelerated at the reconnection site, as does the HXR emission. However, if there is a high temperature (T > 20 MK) HXR source close to the loop top, a contribution of thermal conduction to the EUV brightenings cannot be ruled out.
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Asai, A., Ishii, T.T., Kurokawa, H., Yokoyama, T., and Shimojo, M.: 2003, Astrophys. J. 586, 624.
Attié, D., Cordier, B., Gros, M., Laurent, Ph., Schanne, S., Tauzin, G. et al.: 2003, Astron. Astrophys. 411, L71.
Cargill, P.J., Mariska, J.T., and Antiochos, S.P.: 1995, Astrophys. J. 439, 1034.
Carmichael, H.: 1964, in W.N. Hess (ed.), NASA Symposium on The Physics of Solar Flares, NASA SP-50, NASA, Washington, p. 451.
Cheng, C.-C., Tandberg-Hanssen, E., Bruner, E.C., Orwig, L., Frost, K.J., Kenny, P.J., Woodgate, B.E., Shine, R.A.: 1981, Astrophys. J. 248, L39.
Cheng, C.-C., Tandberg-Hanssen, E., and Orwig, L.E.: 1984, Astrophys. J. 278, 853.
Fletcher, L.: 2002, in A. Wilson (ed.), Solar Variability: From Core to Outer Frontiers, ESA SP-506, ESA Publications Division, Noordwijk, The Netherland, p. 223.
Fletcher, L. and Hudson, H.: 2001, Solar Phys. 204, 69.
Fletcher, L., Pollock, J.A., and Potts, H.E.: 2004, Solar Phys. 222, 279.
Golub, L., Bookbinder, J., DeLuca, E., Karovska, M., Warren, H., Schrijver, C.J., Shine, R., Tarbell, T., Title, A., Wolfson, J., Handy, B., and Kankelborg, C.: 1999, Phys. Plasmas 6, 2205.
Gros, M., Tatischeff, V., Kiener, J., Cordier, B., Chapuis, C., Weidenspointner, G., Vedrenne, G., von Kienlin, A., Diehl, R., Bykov, A., Méndez, M.: 2004, in V. Schönfelder, G. Lichti, and C. Winkler (eds.), Proceedings of the 5th INTEGRAL Workshop on the INTEGRAL Universe, ESA SP-552, ESA Publications Division, Noordwijk, The Netherland, p. 669.
Handy, B.N., Acton, L.W., Kankelborg, C.C., Wolfson, C.J., Akin, D.J., Bruner, M.E. et al.: 1999, Solar Phys. 187, 229.
Hirayama, T.: 1974, Solar Phys. 34, 323.
Huang, G.L. and Ji, H.: 2005, Solar Phys. 229, 227.
Ji, H., Wang, H., Goode, P.R., Jiang, Y., and Yurchyshyn, V.: 2004a, Astrophys. J. 607, L55.
Ji, H., Wang, H., Schmahl, E.J., Qiu, J., and Zhang, Y.: 2004b, Astrophys. J. 605, 938.
Kane, S.R., Frost, K.J., and Donnelly, R.F.: 1979, Astrophys. J. 234, 669.
Kopp, R.A. and Pneuman, G.W.: 1976, Solar Phys. 50, 85.
Krucker, S. and Hudson, H.S.: 2004, in R.W. Walsh, J. Ireland, D. Danesy, and B. Fleck (eds.), Proceedings of the SOHO 15 Workshop, ESA SP-575, ESA Publications Division, Noordwijk, The Netherland, p. 247.
Kundu, M.R., Schmahl, E.J., and Garaimmov, V.I.: 2004, in A.V. Stepanov, E.E. Benevolenskaya, and A.G. Kosovichev (eds.), Multi-Wavelength Investigations of Solar Activity, IAU Symp. 223, Cambridge University Press, Cambridge; New York p. 425.
Kuznetsov, S.N., Kurt, V.G., Yushkov, B.Y., Myagkova, I.N., and Kudela, K.: 2006, Solar System Research 40, 104.
Lin, A.C., Nightingale, R.W., and Tarbell, T.: 2001, Solar Phys. 198, 385.
Masuda, S., Kosugi, T., and Hudson, H.S.: 2001, Solar Phys. 204, 57.
McIntosh, P.S.: 1972, in P.S. McIntosh and M. Dryer (eds.), Solar Activity Observations and Predictions, MIT press, Cambridge, Massachusetts, p. 65.
Moore, R.L., LaRosa, T.N., and Orwig, L.E.: 1995, Astrophys. J. 438, 935.
Moore, R.L., Sterling, A.C., Hudson, H.S., and Lemen, J.R.: 2001, Astrophys. J. 552, 833.
Nagai, F.: 1980, Solar Phys. 68, 351.
Schmieder, B., Mandrini, C.H., Démoulin, P., Pariat, E., Berlicki, A., and Deluca, E.: 2006, Adv. Space Res. 37, 1313.
Smith, D.F. and Auer, L.H.: 1980, Astrophys. J. 238, 1126.
Smith, D.F. and Lilliequist, C.G.: 1979, Astrophys. J. 232, 582.
Sturrock, P.A.: 1966, Nature 211, 695.
Svestka, Z.: 1992, in Z. Svestka, B.V. Jackson, and M.E. Machado (eds.), Eruptive Solar Flares, Springer-Verlag, New York, p. 1.
Vedrenne, G., Roques, J.-P., Schönfelder, V., Mandrou, P., Lichti, G.G., von Kienlin, A. et al.: 2003, Astron. Astrophys. 411, L63.
Wang, Y.M., Ye, P.Z., Zhou, G.P., Wang, S.J., Wang, S., Yan, Y.H., and Wang, J.X.: 2005, Solar Phys. 226, 337.
Warren, H.P. and Warshall, A.D.: 2001, Astrophys. J. 560, L87.
Woodgate, B.E., Shine, R.A., Poland, A.I., and Orwig, L.E.: 1983, Astrophys. J. 265, 530.
Yokoyama, T. and Shibata, K.: 1997, Astrophys. J. 474, L61.
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Su, Y.N., Golub, L., Van Ballegooijen, A.A. et al. Analysis of Magnetic Shear in An X17 Solar Flare on October 28, 2003. Sol Phys 236, 325–349 (2006). https://doi.org/10.1007/s11207-006-0039-z
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DOI: https://doi.org/10.1007/s11207-006-0039-z