Abstract
New perspectives in solar diagnosis have been opened in recent years with the advent of high-resolution soft X-ray spectroscopy for plasmas forming at temperatures above 107 K. The spectra obtained with the soft X-ray spectrometers flown during the last solar maximum on the major space missions dedicated to flares have allowed detailed studies of the hydrodynamic response of coronal loops to impulsive energy deposition and of the formation of the high-temperature plasma as a consequence of such dynamic effects. These studies are possible since high-resolution spectrometers give an accurate measure of both line intensities and profiles in important spectral regions, covering the emission of highly ionized heavy ions, which allow a direct determination of most of the crucial plasma parameters in the flare region. In response to the impulsive energy release in the flare region, while the intensity of soft X-ray lines increases, line profiles show large non-thermal broadenings and strong blue-asymmetries.
There have been important contributions in the understanding of the formation of the flare high-temperature plasma, as an effect of the hydrodynamic response of the solar atmosphere to impulsive chromospheric heating. On the other hand, the attempts to investigate the primary energy release and transport, on the basis of the soft X-ray spectral data, have not yet been entirely successful. Significant differences in the emitted spectra are expected at the very onset of flares for different energy deposition and transport processes, but the sensitivity of the present experiments is still insufficient to detect with good statistics the early stage of flares and, therefore, to allow a reliable discrimination. It is expected that future experiments with higher sensitivity will be of great importance for relating with less ambiguity the observed flare evolution in soft X-rays to the primary energy deposition in the flaring coronal loops.
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Acton, L. W., Culhane, J. L., Gabriel, A. H., and 21 co-authors: 1980, Solar Phys. 65, 53.
Acton, L. W., Canfield, R. C., Gunkler, T. A., Hudson, H. S., Kiplinger, A. L., and Leibacher, J. W.: 1982, Astrophys. J. 263, 409.
Akita, K.: 1985, Ph.D. Thesis, University of Tokyo.
Antonucci, E. and Dennis, B. R.: 1983, Solar Phys. 86, 67.
Antonucci, E. and Dodero, M. A.: 1986, in D. F. Neidig (ed.), The Lower Atmosphere of Solar Flares, NSO/Sacramento Peak, p. 363.
Antonucci, E., Gabriel, A. H., and Dennis, B. R.: 1984, Astrophys. J. 287, 917.
Antonucci, E., Rosner, R., and Tsinganos, K.: 1986, Astrophys. J. 301, 975.
Antonucci, E., Rosner, R., and Tsinganos, K.: 1987, in V. E. Stepanov and V. N. Obridko (eds.), Solar Maximum Analysis, Science Press, p. 446.
Antonucci, E., Dodero, M. A., and Martin, R.: 1989, Astrophys. J. Suppl. (submitted).
Antonucci, E., Gabriel, A. H., and 7 co-authors: 1982, Solar Phys. 78, 107.
Antonucci, E., Dennis, B. R., Gabriel, A. H., and Simnett, G. M.: 1985, Solar Phys. 96, 129.
Antonucci, E., Dodero, M. A., Peres, G., Serio, S., and Rosner, R.: 1987, Astrophys. J. 322, 522.
Antonucci, E., Dodero, M. A., Peres, G., Reale, F., and Serio, S.: 1989 (in preparation).
Bhalla, C. P., Gabriel, A. H., and Presnyakov, L. P.: 1975, Monthly Notices Roy. Astron. Soc. 172, 359.
Bornmann, P. L.: 1987, Astrophys. J. 313, 449.
Bruner, M. E., Crannell, C. J., Goetz, F., Magun, A., and McKenzie, D. L.: 1988, NASA Technical Memorandum 87815.
Canfield, R. C.: 1986, Adv. Space Res. 6, 167.
Canfield, R. C., Gunkler, T. A., and Ricchiazzi, P. J.: 1985, Astrophys. J. 282, 296.
Canfield, R. C., Zarro, D. M., Metcalf, T. R., and Lemen, J. R.: 1989, Astrophys. J. (submitted).
Cheng, C.-C., Karpen, J. T., and Doschek, G. A.: 1984, Astrophys. J. 286, 787.
de Jager, C.: 1985, Solar Phys. 98, 267.
Doschek, G. A.: 1983, Solar Phys. 86, 9.
Doschek, G. A., Feldman, U., Landecker, P. B., and McKenzie, D. L.: 1981, Astrophys. J. 249, 372.
Doschek, G. A. et al.: 1986, NASA Conference Publ. 2439, 4-1/4-42.
Dubau, J., Gabriel, A. H., Loulergue, M., Steenman-Clark, L., and Volonté, S.: 1981, Monthly Notices Roy. Astron. Soc. 195, 705.
Emslie, A. G. and Alexander, D.: 1987, Solar Phys. 110, 295.
Feldman, V., Doschek, G. A., Kreplin, R. W., and Mariska, J. T.: 1980, Astrophys. J. 241, 1175.
Fisher, G. H., Canfield, R. C., and McClymont, A. N.: 1984, Astrophys. J. 281, L79.
Fisher, G. H., Canfield, R. C., and McClymont, A. N.: 1985, Astrophys. J. 289, 434.
Gabriel, A. H.: 1972, Monthly Notices Roy. Astron. Soc. 160, 99.
Gabriel, A. H. and Jordan, C.: 1969, Monthly Notices Roy. Astron. Soc. 145, 241.
Grineva, Y. I., Karev, V. I., Korneev, V. V., Krutov, V. V., Mandelstam, S. L., Vainstein, L. A., Vasilyev, B. N., and Zhitnik, I. A.: 1973, Solar Phys. 29, 441.
Gunkler, T. A., Acton, L. W., Canfield, R. C., and Kiplinger, A. L.: 1984, Astrophys. J. 285, 835.
Hiei, E. and Widing, K. G.: 1979, Solar Phys. 61, 407.
Ichimoto, K. and Kurokawa, K.: 1984, Solar Phys. 93, 105.
Karpen, J. T., Doschek, G. A., and Seely, J. F.: 1986, Astrophys. J. 306, 327.
Lin, R. P., Schwartz, R. A., Pelling, R. M., and Hurley, K. C.: 1981, Astrophys. J. 251, L109.
Linford, G. A. and Wolfson, C. J.: 1989, Astrophys. J. (in press).
Linford, G. A., Lemen, J. R., and Strong, K. T.: 1989, Adv. Space Res. (in press).
Martens, P. C. H., Van den Oord, G. H. J., and Hoyng, P.: 1985, Solar Phys. 96, 253.
McKenzie, D. L., Broussard, R. M., Landecker, P. B., Rugge, H. R., Young, R. M., Doschek, G. A., and Feldman, U.: 1980, Astrophys. J. 238, L43.
MacNeice, P.: 1986, Solar Phys. 103, 47.
MacNeice, P., McWhirter, R. W. P., Spicer, D. S., and Burgess, A.: 1984, Solar Phys. 90, 357.
Nagai, F. and Emslie, A. G.: 1984, Astrophys. J. 279, 896.
Neupert, W. M., Gates, W., Swartz, M., and Young, R.: 1967, Astrophys. J. 149, L79.
Parker, E. N.: 1983, Geophys. Astrophys. Fluid Dyn. 24, 79.
Parker, E. N.: 1987, Solar Phys. 111, 297.
Parmar, A. N., Culhane, J. L., Rapley, C. G., Antonucci, E., Gabriel, A. H., and Loulergue, M.: 1981, Monthly Notices Roy. Astron. Soc. 197, 29.
Saba, J. L. R. et al.: 1989 (in preparation).
Smith, D. F. and Harmony, D. W.: 1982, Astrophys. J. 252, 800.
Somov, B. V., Syrovatskii, S. I., and Spektor, A. R.: 1981, Solar Phys. 73, 145.
Somov, B. V., Sermulina, B. J., and Spektor, A. R.: 1982, Solar Phys. 81, 281.
Sweet, P. A.: 1969, Ann. Rev. Astron. Astrophys. 7, 149.
Takakura, T. et al.: 1983, Astrophys. J. 270, L83.
Tanaka, K.: 1986, Publ. Astron. Soc. Japan 38, 225.
Tanaka, K.: 1987, Publ. Astron. Soc. Japan 39, 1.
Tanaka, K. and Zirin, H.: 1985, Astrophys. J. 299, 1036.
Tanaka, K., Watanabe, T., Nishi, K., and Akita, K.: 1982a, Astrophys. J. 254, L59.
Tanaka, K., Akita, K., Watanabe, T., and Nishi, K.: 1982b, Hinotori Symposium on Solar Flares, Tokyo, p. 43.
Tsuneta, S.: 1987, Solar Phys. 113, 35.
Tsuneta, S., Nitta, N., Ohki, K., Takakura, T., Tanaka, K., and 4 co-authors: 1984, Astrophys. J. 284, 827.
Uchida, Y. and Shibata, K.: 1988, Solar Phys. 116, 291.
Watanabe, T.: 1987, Solar Phys. 113, 107.
Winglee, R. M., Pritchett, P. L., and Dulk, G. A.: 1989, Astrophys. J. (in press).
Wolfson, C. J., Doyle, J. G., Leibacher, J. W., and Phillips, K. J. H.: 1983, Astrophys. J. 269, 319.
Zarro, D. M., Strong, K. T., Canfield, R. C., Metcalf, T., and Saba, J. L. R.: 1989, Astrophys. J. (submitted).
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Antonucci, E. Solar flare spectral diagnosis: Present and future. Sol Phys 121, 31–60 (1989). https://doi.org/10.1007/BF00161686
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DOI: https://doi.org/10.1007/BF00161686