Abstract
The major results from SMM are presented as they relate to our understanding of the energy release and particle transportation processes that lead to the high-energy X-ray aspects of solar flares. Evidence is reviewed for a 152–158 day periodicity in various aspects of solar activity including the rate of occurrence of hard X-ray and gamma-ray flares. The statistical properties of over 7000 hard X-ray flares detected with the Hard X-Ray Burst Spectrometer are presented including the spectrum of peak rates and the distribution of the photon number spectrum. A flare classification scheme introduced by Tanaka is used to divide flares into three different types. Type A flares have purely thermal, compact sources with very steep hard X-ray spectra. Type B flares are impulsive bursts which show double footpoints in hard X-rays, and soft-hard-soft spectral evolution. Type C flares have gradually varying hard X-ray and microwave fluxes from high altitudes and show hardening of the X-ray spectrum through the peak and on the decay. SMM data are presented for examples of type B and type C events. New results are presented showing coincident hard X-rays, O v, and UV continuum observations in type B events with a time resolution of ≤128 ms. The subsecond variations in the hard X-ray flux during ≲ 10% of the stronger events are discussed and the fastest observed variation in a time of 20 ms is presented. The properties of type C flares are presented as determined primarily from the non-imaged hard X-ray and microwave spectral data. A model based on the association of type C flares and coronal mass ejections is presented to explain many of the characteristics of these gradual flares.
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Acton, L. W., Culhane, J. L., Gabriel, A. H., and 21 co-authors: 1980, Solar Phys. 65, 53.
Antonucci, E., Gabriel, A. H., and Dennis, B. R.: 1984, Astrophys. J. 287, 179.
Bai, T.: 1982, in R. E. Lingenfelter, H. S. Hudson, and D. M. Worrall (eds.), Gamma Ray Transients and Related Astrophysical Phenomena, American Institute of Physics, New York, p. 409.
Bai, T. and Dennis, B. R.: 1985, Astrophys. J. 292, 699.
Bai, T. and Ramaty, R.: 1979, Astrophys. J. 227, 1072.
Bai, T., Hudson, H. S., Pelling, R. M., Lin, R. P., Schwartz, R. A., and von Rosenvinge, T. T.: 1983, Astrophys. J. 267, 433.
Bai, T., Kiplinger, A. L., and Dennis, B. R.: 1985, Astrophys. J. (in preparation).
Batchelor, D. A.: 1984, Ph.D. Thesis, University of North Carolina at Chapel Hill; also NASA TM86102.
Bogert, R. S. and Bai, T.: 1985, presented at the Solar Physics Division meeting Tucson, May 13–15, 1985.
Brown, J. C.: 1971, Solar Phys. 18, 489.
Cheng, C.-C., Tandberg-Hanssen, E., Bruner, E. C., Orwig, L. E., Frost, K. J., Woodgate, B. E., and Shine, R. A.: 1981, Astrophys. J. 248, L39.
Cliver, E. W.: 1983, Solar Phys. 84, 347.
Cliver, E. W., Dennis, B. R., Kane, S. R., Neidig, D. F., Sheeley, N. R. Jr., and Koomen, M. J.: 1985, Astrophys. J. (submitted).
Cook, J. W. and Brueckner, G. E.: 1979, Astrophys. J. 227, 645.
Crannell, C. J., Frost, K. J., Mätzler, C., Ohki, K., and Saba, J. L.: 1978, Astrophys. J. 223, 620.
Datlowe, D. W.: 1975, Space Sci. Instr. 1, 389.
Datlowe, D. W.: 1977, Nucl. Inst. Methods 145, 365.
Datlowe, D. W., Elcan M. J., and Hudson, H. S.: 1974, Solar Phys. 39, 155.
Deeming, T. J.: 1975, Astrophys. Space Sci. 36, 137.
Dennis, B. R., Frost, K. J., and Orwig, L. E.: 1981, Astrophys. J. 244, L167.
Dennis, B. R., Frost, K. J., Orwig, L. E., Kiplinger, A. L., Dennis, H. E., Gibson, B. R., Kennard, G. S., and Tolbert, A. K.: 1983, NASA TM84998.
Dennis, B. R., Kiplinger, A. L., Orwig, L. E., and Frost, K. J.: 1985, Proc. 2nd India-U.S. Workshop on Solar Terrestrial Physics, January 1984, New Delhi, India; also NASA TM86187.
Donnelly, R. F. and Kane, S. R.: 1978, Astrophys. J. 222, 1043.
Duijveman, A. and Hoyng, P.: 1983, Solar Phys. 86, 289.
Duijveman, A., Hoyng, P., and Machado, M. E.: 1982, Solar Phys. 81, 137.
Emslie, A. G. and Nagai, F.: 1984, Astrophys. J. 279, 896.
Emslie, A. G. and Vlahos, L.: 1980, Astrophys. J. 242, 359.
Hoyng, P., Marsh, K. A., Zirin, H., and Dennis, B. R.: 1983, Astrophys. J. 268, 865.
Hurley, K., Niel, M., Talon, R., Estulin, I. V., and Dolidge, V. Ch.: 1983, Solar Phys. 86, 367.
Kahler, S. W.: 1982, J. Geophys. Rev. 87, 3439.
Kane, S. R.: 1973, in R. Ramaty and R. G. Stone (eds.), High Energy Phenomena in the Sun, NASA SP-342, p. 55.
Kane, S. R. and Anderson, K. A.: 1970, Astrophys. J. 162, 1003.
Kane, S. R., Frost, K. J., and Donnelly, R. F.: 1979, Astrophys. J. 234, 669.
Kawabata, K., Ogawa, H., and Suzuki, I.: 1983, Solar Phys. 86, 247.
Kiplinger, A. L., Dennis, B. R., Emslie, A. G., Frost, K. J., and Orwig, L. E.: 1983a, Astrophys. J. 265, L99.
Kiplinger, A. L., Dennis, B. R., Frost, K. J., and Orwig, L. E.: 1983b, Astrophys. J. 273, 783.
Kiplinger, A. L., Dennis, B. R., Frost, K. J., and Orwig, L. E.: 1984, Astrophys. J. 287, L105.
Kiplinger, A. L., Dennis, B. R., and Orwig, L. E.: 1985, Bull. Am. Astron. Soc. 16, 891.
Leach, J. and Petrosian, V.: 1983, Astrophys. J. 269, 715.
Lin, R. P. and Hudson, H. S.: 1976, Solar Phys. 50, 153.
Lin, R. P., Schwartz, R. A., Kane, S. R., Pelling, R. M., and Hurley, K. C.: 1984, Astrophys. J. 283, 421.
Lin, R. P., Schwartz, R. A., Pelling, R. M., and Hurley, K. C.: 1981, Astrophys. J. 251, L109.
MacKinnon, A. L., Brown, J. C., and Hayward, J.: 1984, preprint.
Mariska, J. T. and Poland, A. I.: 1985, Solar Phys. 96, 317.
Ohki, K., Takakura, T., Tsunata, S., and Nitta, N.: 1983, Solar Phys. 86, 301.
Orwig, L. E., Frost, K. J., and Dennis, B. R.: 1981, Astrophys. J. 244, L163.
Pallavicini, R., Serio, S., and Vaiana, G. S.: 1977, Astrophys. J. 216, 108.
Poland, A. I., Machado, M. E., Wolfson, C. J., Frost, K. J., Woodgate, B. E., Shine, R. A., Kenny, P. J., Cheng, C.-C., Tandberg-Hanssen, E. A., Bruner, E. C., and Henze, W.: 1982, Solar Phys. 78, 201.
Poland, A. I., Orwig, L. E., Mariska, J. T., Nakatsuka, R., and Auer, L. H.: 1985, Astrophys. J. 280, 457.
Pryor, H., Pierce, M. J., Speich, D. M., Fesq, L. M., Spear, K. A., Nelson, J. J., and McGovern, J. G.: 1981, Solar Maximum Mission Event Listing, Internal Document of the SMM Data Analysis Center, NASA, GSFC.
Rieger, E., Share, G. H., Forrest, D. J., Kanback, G., Reppin, C., and Chupp, E. L.: 1985, Nature 312, 623.
Rust, D. M.: 1984, Adv. Space Res. 4, 191.
Rust, D. M., Simnett, G. M., and Smith, D. F.: 1985, Astrophys. J. 288, 401.
Smith, D. F.: 1985, Astrophys. J. 288, 801.
Švestka, Z., Schrijver, J., Somov, B., Dennis, B. R., Woodgate, B. E., Fürst, E., Hirth, W., Klein, L., and Raoult, A.: 1983, Solar Phys. 85, 313.
Tanaka, K., 1983, in P. B. Byrne and M. Rodono (eds.), ‘Activity in Red-Dwarf Stars’, IAU Colloq. 71, 307.
Tanaka, K., Nitta, N., Akita, K., and Watanabe, T.: 1983, Solar Phys. 86, 91.
Tramiel, L. J., Charan, G. A., and Novick, R.: 1984, Astrophys. J. 280, 440.
Tsuneta, S.: 1983, in J.-C. Pecker and Y. Uchida (eds.), Proc. Japan-France Seminar on Active Phenomena in the Outer Atmosphere of the Sun and Stars, 3–7 October 1983, CNRS and Observatoire de Paris, p. 243.
Tsuneta, S.: 1985, Astrophys. J. 290, 353.
Tsuneta, S., Nitta, N., Ohki, K., Takakura, T., Tanaka, K., Makishima, K., Murakami, T., Oda, M., and Ogawara, Y.: 1984a, Astrophys. J. 284, 827.
Tsuneta, S., Takakura, T., Nitta, N., Ohki, K., Tanaka, K., Makishima, K., Murakami, T., Oda, M., Ogawara, Y., and Kondo, I.: 1984b, Astrophys. J. 280, 887.
Tucker, W. H.: 1975, Radiation Processes in Astrophysics, MIT Press, Cambridge.
Wolff, C. L.: 1983, Astrophys. J. 264, 667.
Woodgate, B. E.: 1984, Adv. Space Res. 4, 393.
Woodgate, B. E., Shine, R. A., Poland, A. I., and Orwig, L. E.: 1983, Astrophys. J. 265, 530.
Wu, S. T., de Jager, C., Dennis, B. R., Hudson, H. S., Simnett, G. M., Strong, K. T., Bentley, R. D., Bornmann, P. L., Bruner, M. E., Cargill, P. J., Crannell, C. J., Doyle, J. G., Hyder, C. L., Kopp, R. A., Lemen, J. R., Martin, S. F., Pallavicini, R., Peres, G., Serio, S., Sylvester, J., and Veck, N. J.: 1985, in M. R. Kundu and B. E. Woodgate (eds.), Proc. SMM Workshop on Solar Flares, NASA, (in preparation).
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Dennis, B.R. Solar hard X-ray bursts. Sol Phys 100, 465–490 (1985). https://doi.org/10.1007/BF00158441
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DOI: https://doi.org/10.1007/BF00158441