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Solar Hard X-Ray and Gamma-Ray Observations from GRANAT1

Published online by Cambridge University Press:  12 April 2016

N. Vilmer*
Affiliation:
DASOP—Observatoire de Paris, Section d’Astrophysique de Meudon, F92195 Meudon-Cedex, France

Abstract

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Hard X-rays and gamma-rays are the most direct signature of the energetic electrons and ions which are accelerated during solar flares. Since the beginning of 1990 the PHEBUS instrument and the SIGMA anticoincidence shield aboard GRANAT have provided hard X-ray and gamma-ray observations of solar bursts in the energy range 0.075-124 and 0.200-15 MeV, respectively. After a brief description of the experiments, we present some results obtained on solar bursts recorded in 1990 and 1991 June. Special emphasis is given to the results related with particle acceleration during solar flares.

The first part of the review is devoted to the constraints obtained on the electron acceleration timescale through the analysis of the temporal characteristics of the bursts. Combined studies of hard X-ray and gamma-ray emissions from PHEBUS and radio emissions from the Nançay Multifrequency Radioheliograph are used to infer constraints on the coronal magnetic topology involved in flares. The characteristics (location, spectrum) of the radio-emitting sources are found to vary within a flare from one hard X-ray peak to the other. Hard X-ray and gamma-ray burst onsets and rapid increases of the > 10 MeV emission are coincident with changes in the associated radio emission pattern. These results will be discussed in the context of the flare energy release.

The second part of the paper concerns the heliocentric angle distribution of > 10 MeV events and presents more detailed observations of some of the largest flares in the gamma-ray line and the high-energy domains produced by ultrarelativistic electrons and > 100 MeV nucleon−1 ions. The PHEBUS observations of the gamma-ray line flare of 11 June 1991 have been used to deduce the hardness of the accelerated ion spectrum. The link between the main part of the flare and the late long-lasting >50 MeV emission detected by EGRET/COMPTON is discussed. Finally some observations of the large 1990 May 24 flare which produced a large neutron event at ground level are presented.

Subject headings: acceleration of particles — Sun: flares — Sun: radio radiation — Sun: X-rays, gamma rays

Type
Solar Flares
Copyright
Copyright © The American Astronomical Society 1994

Footnotes

2

On behalf of the solar GRANAT collaboration.

1

Invited review at IAU Colloquium 142, “Particle Acceleration Phenomena in Astrophysical Plasmas.”

References

Achterberg, A., & Kuijpers, J. 1984, A&A, 130, 111 Google Scholar
Akimov, V.V., & GAMMAI Team. 1991, in Proc. 22d Internat. Cosmic-Ray Conf. (Dublin), SH 2.3-6, 73 Google Scholar
Barat, C., et al. 1988, in Nuclear Spectroscopy of Astrophysical Sources, ed. Share, G.H. & Gehrels, N. (New York: AIP), 395 Google Scholar
Benz, A.O., & Aschwanden, M.J. 1991, in Lecture Notes in Physics 399, Eruptive Solar Flares, ed. Svestka, Z., Jackson, B.V., & Machado, M.E. (New York: Springer), 363 Google Scholar
Bruggmann, G., Vilmer, N., Klein, K.L., & Kane, S.R. 1993, Sol. Phys., in pressGoogle Scholar
Chupp, E.L. 1982, in Gamma-Ray Transients and Related Phenomena, ed. Lingenfelter, R.E., Hudson, H.S., & Worall, D.M. (New York: AIP), 363 Google Scholar
Chupp, E.L. 1988, Sol. Phys., 118, 137 Google Scholar
Chupp, E.L. 1990a, Science, 250, 229 Google Scholar
Chupp, E.L. 1990b, ApJS, 73, 213 CrossRefGoogle Scholar
Chupp, E.L., Forrest, D.J., Higbie, P.R., Suri, A.N., Tsai, C., & Dunphy, P.P. 1973, Nature, 241, 33 CrossRefGoogle Scholar
Chupp, E.L., et al. 1981, ApJ, 244, L171 Google Scholar
Chupp, E.L., Trottet, G., Marschhaüser, H., Pick, M., Soru-Escaut, I., Rieger, E., & Dunphy, P.P. 1993, A&A, 275, 602 Google Scholar
Dennis, B.R. 1988, Sol. Phys., 118, 49 CrossRefGoogle Scholar
Desai, U.D., et al. 1987, ApJ, 319, 567 Google Scholar
Forrest, D.J., Vestrand, W.T., Chupp, E.L., Rieger, E., Cooper, J., & Share, G.H. 1985, in Proc. 19th Internat. Cosmic-Ray Conf. (La Jolla) (NASA CP-2376), 4, 146 Google Scholar
Golonetskii, S.V., et al. 1991, Soviet Astron. Lett, 17, 83 Google Scholar
Heristchi, D.J. 1986, ApJ, 311, 474 Google Scholar
Hua, X.M., & Lingenfelter, R.E. 1987a, Sol. Phys., 107, 351 CrossRefGoogle Scholar
Hua, X.M., & Lingenfelter, R.E. 1987b, ApJ, 319, 555 Google Scholar
Hulot, E., Vilmer, N., & Trottet, G. 1989, A&A, 213, 383 Google Scholar
Hurley, K., Niel, M., Talon, R., Estulin, I., & Dolidze, V.C. 1983, ApJ, 265, 1076 Google Scholar
Kanbach, G., et al. 1993, A&AS, 97, 349 Google Scholar
Kane, S.R., Chupp, E.L., Forrest, G.H., Share, G.H., & Rieger, E. 1986, ApJ, 300, L95 Google Scholar
Kawabata, K., et al. 1982, in Proc. Hinotori Symp. on Solar Flares (Institute of Space and Astronautical Science), 168 Google Scholar
Kiplinger, A.L., Dennis, B.R., Emslie, A.G., Frost, K.G., & Orwig, L.E. 1983, ApJ, 265, L99 CrossRefGoogle Scholar
Kocharov, L. G., & Kovaltsov, G.A. 1990, Sol. Phys., 125, 67 Google Scholar
Leikov, N.G., et al. 1993, A&AS, 97, 345 Google Scholar
Machado, M.E., Emslie, A.G., Fishman, G.J., Meegan, G., Wilson, R., & Pachiesas, W. 1993, Adv. Space Res. (COSPAR), 13, 175 Google Scholar
Machado, M.E., Moore, R.L., Hernandez, A., Rovira, M.G., Hagyard, M.J. & Smith, J.B. 1988, ApJ, 326, 425 Google Scholar
MacKinnon, A.L., & Brown, J.C. 1989, A&A, 215, 371 Google Scholar
Mandzhavidze, N., & Ramaty, R. 1992a, ApJ, 389, 739 Google Scholar
Mandzhavidze, N., & Ramaty, R. 1992b, ApJ, 396, Ll11 Google Scholar
Mandzhavidze, N., & Ramaty, R. 1993, Nucl. Phys., in pressGoogle Scholar
McTiernan, J.M., & Petrosian, V. 1991, ApJ, 379, 381 CrossRefGoogle Scholar
Murphy, R.J., et al. 1993, in Proc. Compton Symp., in pressGoogle Scholar
Nakajima, H. 1983, Sol. Phys., 86, 427 Google Scholar
Pelaez, F., et al. 1992, Sol. Phys., 140, 121 Google Scholar
Pelaez, F., et al. 1991, in 22d Internat. Cosmic-Ray Conf. Proc., SH2.3-11, 89 Google Scholar
Prince, T.A., Forrest, D.J., Chupp, E.L., Kanbach, G., & Share, G.H. 1983, in 18th Internat. Cosmic-Ray Conf. Proc., 4, 79 Google Scholar
Pyle, K.R., Shea, M.A., & Smart, D.F. 1991, in 22d Internat. Cosmic-Ray Proc., SH2.2-7, 57 Google Scholar
Radioheliograph Group 1989, Sol. Phys., 120, 193 Google Scholar
Ramaty, R., & Mandzhavidze, N. 1993, in Proc. Compton Symp., in pressGoogle Scholar
Ramaty, R., Mandzhavidze, N., Kozlovsky, B., & Skibo, J. 1993, Adv. Space Res. (COSPAR), in pressGoogle Scholar
Ramaty, R., Miller, J.A., Hua, X.M., & Lingenfelter, R.E. 1988, in Nuclear Spectroscopy of Astrophysical Sources, ed. Share, G.H. & Gehreis, N. (New York: AIP), 217 Google Scholar
Ramaty, R., & Murphy, R. 1987, Space Science Rev., 45, 213 Google Scholar
Raoult, A., Pick, M., Dennis, B.R., & Kane, S.R. 1985, ApJ, 299, 1027 Google Scholar
Rieger, E. 1989, Sol. Phys., 121, 323 Google Scholar
Rieger, E. 1990, in Gamma-Ray Line Astrophysics Conf. Proc., ed. Durouchoux, P. & Prantzos, N. (New York: AIP), 421 Google Scholar
Rieger, E., & Marschhaüser, H. 1990, in Proc 3d MAX’91/SMM Workshop on Solar Flares: Observations and Theory, ed. Winglee, R.M. & Kiplinger, A.L. (Boulder: Univ. Colorado Press), 68 Google Scholar
Rieger, E., Reppin, C., Kanbach, G., Forrest, D.J., Chupp, E.L., & Share, G.H. 1983, in Proc 18th Internat. Cosmic-Ray Conf. (Paris), 10, 338 Google Scholar
Ryan, J., et al. 1993, in Proc. Compton Symp., in pressGoogle Scholar
Shea, M.A., Smart, D.F., & Pyle, K.R. 1992, Geophys. Res. Lett., 18, 1655 Google Scholar
Talon, R., Barat, C., Dezalay, J.P., Vilmer, N., Trottet, G., Sunyaev, R., Terekhov, O., & Kuznetsov, A. 1993a, Adv. Space Res. (COSPAR), 13, 171 Google Scholar
Talon, R., Trottet, G., Vilmer, N., Barat, C., Dezalay, J.P., Sunyaev, R., Terekhov, O., & Kuznetsov, A. 1993b, Sol. Phys., 147, 137 Google Scholar
Talon, R., Vedrenne, G., Melioransky, A.S., Pissarenko, N, Shamolin, V.F., & Likin, O.B. 1975, in IAU Symp. 68, Solar Gamma-, X-, and EUV Radiation, ed. Kane, S.R. (Dordrecht: Reidel), 315 Google Scholar
Terekhov, O.V., et al. 1993, COSPAR abstracts E3-5, 5.10Google Scholar
Trottet, G. 1986, Sol. Phys., 104, 145 CrossRefGoogle Scholar
Trottet, G., Vilmer, N., Barat, C., Dezalay, J.P., Talon, R., Sunyaev, R., Kuznetsov, A., & Terekhov, O. 1993a, A&AS, 97, 337 Google Scholar
Trottet, G., Vilmer, N., Barat, C., Dezalay, J.P., Talon, R., Sunyaev, R., Terekhov, O., & Kuznetsov, A. 1993b, Adv. Space Res. (COSPAR), 13, 285 Google Scholar
Van Beek, H.F., de Feiter, L.D., & de Jager, C. 1974, Space Res., 14, 477 Google Scholar
Vestrand, W.T., Forrest, D.J., Chupp, E.L., Rieger, E., & Share, G.H. 1987, ApJ, 322, 1010 Google Scholar
Vestrand, W.T., Forrest, D.J., & Rieger, E. 1991, in Proc. 22d Internat. Cosmic-Ray Conf. (Dublin), SH2.3-5, 69 Google Scholar
Vilmer, N. 1987, Sol. Phys., 111, 207 CrossRefGoogle Scholar
Wang, H.T., & Ramaty, R. 1974, Sol. Phys., 36, 129 Google Scholar
Willson, R.F., Klein, K.L., Kerdraon, A., Lang, K.R., & Trottet, G. 1990, ApJ, 357, 662 Google Scholar
Wu, S.T., et al. 1986, in Energetic Phenomena on the Sun, ed. Kundu, M. & Woodgate, B. (NASA CP-2439), 51 Google Scholar
Wülzer, J.P., Canfield, R.C., & Rieger, E. 1990, in Proc. 3d MAX’91/ SMM Workshop on Solar Flares: Observations and Theory, ed. Winglee, R. M. & Kiplinger, A.L. (Boulder: Univ. Colorado Press), 149 Google Scholar
Yoshimori, M. 1989, Space Sci. Rev., 51, 85 Google Scholar
Yoshimori, M., Takai, Y., Morimoto, K., Suga, K., & Ohki, K. 1992, PASJ, 44, L107 Google Scholar