Abstract
The HXS and GRS detectors on Yohkoh observed the 14 July 2000, X5.7 flare, beginning at ∼ 10:20 UT, ∼ 4 min before the peak in soft X-rays. The hard X-rays and γ-rays peaked ∼ 3 min later at ∼ 10:27 UT. Solar γ-ray emission lasted until ∼ 10:40 UT. Impact of high-energy ions at the Sun is revealed by the γ-ray lines from neutron capture, annihilation radiation and de-excitation that are visible above the bremsstrahlung continuum. From measurement of these lines we find that the flare-averaged spectrum of accelerated protons is consistent with a power law ge10 MeV with index 3.14±0.15 and flux 1.1×1032 protons MeV−1 at 10 MeV. We estimate that there were ∼1.5×1030 erg in accelerated ions if the power law extended without a break down to 1 MeV; this is about 1% of the energy in electrons > 20 keV from measurements of the hard X-rays. We find no evidence for spectral hardening in the hard X-rays that has been suggested as a predictor for the occurrence of solar energetic particle (SEP) events. This was the third largest proton event above 10 MeV since 1976. The GRS and HXS also observed γ-ray lines and continuum produced by the impact of SEP on the Earth's atmosphere beginning about 13 UT on 14 July. These measurements show that the SEP spectrum softened considerably over the next 24 hours. We compare these measurements with proton measurements in space.
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References
Brown, J. C.: 1971, Solar Phys. 18, 489
Kiplinger, A. L.: 1995, Astrophys. J. 453, 973
Klein, K.-L., Trottet, G., Lantos, P., and Delaboudinière, J.-P.: 2001, Astron. Astrophys. 373, 1073
Lampton, M., Margon, B., and Bowyer, S.: 1976, Astrophys. J. 208, 177
Lin, R. P. et al.: 2000, in R. Ramaty and N. Mandzhavidze (eds.), High Energy Solar Physics–Anticipating HESSI, Am. Soc. Pacific Conf. Series 206, San Francisco, p. 1
MacKinnon, A. L.: 1989, Astron. Astrophys. 226, 284
Ramaty, R. 1986, in P. A. Sturrock, T. E. Holzer, D. M. Mihalas, and R. K. Ulrich, (eds.), Physics of the Sun, D. Reidel Publ. Co., Geophysics and Astrophysics Monographs, Dordrecht, p. 291
Ramaty, R. and Mandzhavidze, N.: 2000, in P. C. H. Martens, S. Tsuruta, and M. A. Weber (eds.), Highly Energetic Physical Processes and Mechanisms for Emission from Astrophysical Plasmas, IAU Symposium 195, p. 123
Ramaty, R., Mandzhavidze, N., and Kozlovsky, B.: 1996, in R. Ramaty, N. Mandzhavidze, and X.-M Hua (eds.), High Energy Solar Phys., Am. Inst. Phys. Conf. Proc. 374, New York, p. 172
Ramaty, R., Mandzhavidze, N., Kozlovsky, B., and Murphy, R. J.: 1995, Astrophys. J. 455, L193
Ramaty, R., Mandzhavidze, N., Kozlovsky, B., and Skibo, J. G.: 1993, Adv. Space Res. 13, 275
Reames, D. V.: 1995, Adv. Space Res., 15, 41
Reames, D. V., Meyer, J. P., and von Rosenvinge, T. T.: 1994, Astrophys. J. Suppl. 90, 649
Share, G. H. and Murphy, R. J.: 1995, Astrophys. J. 452, 933
Share, G. H. and Murphy, R. J.: 2000, in R. Ramaty and N. Mandzhavidze (eds.), High Energy Solar Physics-Anticipating HESSI, Am. Soc. Pacific Conf. Series 206, San Francisco, p. 377
Share, G. H. and Murphy, R. J.: 2001, J. Geophys. Res. 106, 77
Share, G. H., Murphy, R. J., and Newton, E.K.: 2001, Solar Phys. 201, 191
Simnett, G. M.: 1995, Space Sci. Rev. 73, 387
Yoshimori, M., Okudaira, K., Hirasima, Y., Igarashi, T., Akasak, M., Takai, Y., Morimoto, K., Watan-abe, T., Ohki, K., Nishimura, J., Yamagami, T., Ogawara, Y., and Kondo, I.: 1991, Solar Phys. 136, 69
Yoshimori, Suga, K., Morimoto, K., Hiraoka, T., Sato, J., Kawabata, K., and Ohki, K.: 1994, Astrophys. J. Suppl. 90, 639
Yoshimori, M., Suga, K., Saita, N., and Shiozawa, A.: 2000, Adv. Space Res. 25, 1801
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Share, G., Murphy, R., Tylka, A. et al. Gamma-Ray Line Observations of the 2000 July 14 Flare and SEP Impact on the Earth. Sol Phys 204, 41–53 (2001). https://doi.org/10.1023/A:1014297617919
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DOI: https://doi.org/10.1023/A:1014297617919