Hostname: page-component-848d4c4894-xfwgj Total loading time: 0 Render date: 2024-06-29T05:44:38.060Z Has data issue: false hasContentIssue false
  • English
  • Français

Particle Acceleration in Solar Flares

Published online by Cambridge University Press:  12 April 2016

Loukas Vlahos
Loukas Vlahos*
Affiliation:
Department of Physics, University of Thessaloniki, 54006 Thessaloniki, Greece

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Particle acceleration during solar flares is a complex process where the main ‘actors’ (Direct (D.C.) or turbulent electric fields) are hidden from us. It is easy to construct a successful particle accelertion model if we are allowed to impose on the flaring region arbitrary conditions (e.g., strength and scale length of the D.C. or turbulent electric fields), but then we have not solved the acceleration problem; we have simply re-defined it. We outline in this review three recent observations which indicate that the following physical processes may happen during solar flares : (1) Release of energy in a large number of microflares ; (2) short time-scales; (3) small length scales; and (4) coherent radiation and acceleration sources. We propose that these new findings force us to reformulate the acceleration process inside a flaring active region assuming that a large number of reconnection sites will burst almost simultaneously. All the well-known acceleration mechanisms (electric fields, turbulent fields, shock waves, etc.) reviewed briefly here, can be used in a statistical model where each particle is gaining energy through its interaction with many small reconnection sites.

Type
Research Article
Information
International Astronomical Union Colloquium , Volume 104 , Issue 1: Solar and Stellar Flares , 1989 , pp. 431 - 447
Copyright
Copyright © Kluwer 1989

References

Alfvén, H. and Carlqvist, P.: 1967, Solar Phys. 1, 220.Google Scholar
Ambrosiano, J. J. Matthaeus, D., Goldstein, M. L., and Plante, D. R.: 1989, J. Geophys. Res. (in press).Google Scholar
Benz, A. O.: 1985, Solar Phys. 96, 357.CrossRefGoogle Scholar
Benz, A. O. and Smith, D.: 1987, Solar Phys. 107, 299.Google Scholar
Benz, A. O., Zlobec, P., and Jaeggi, M.: 1982, Astron. Astrophys. 109, 305.Google Scholar
Benz, A. O., Ashwanden, M. J., and Wiehl, J. J.: 1984, Decimelric Radio Emission During Solar Flares, Kunming Workshop Proceedings.Google Scholar
Block, L. P.: 1978, Astrophys. Space Sci. 55, 59.Google Scholar
Buchner, J. and Zeleny, L. M.: 1986, Proceedings of the Joint Varena-Abastumani International school and Workshop on ‘Plasma Astrophysics', ESA SP-251, p. 195.Google Scholar
Bulanov, S. V.: 1986, Proceedings of the Joint Varena-Abastumani International School and Workshop on 'Plasma Astrophysics', ESA SP-251, p. 185.Google Scholar
Cargill, P. J.: 1989, J. Geophys. Res. (submitted).Google Scholar
Cargill, P. J. and Goodrich, C. C.: 1987, Phys. Fluids 30, 2504.CrossRefGoogle Scholar
Cargill, P. J., Goodrich, C. C., and Vlahos, L.: 1988, Astron. Astrophys. 189, 254.Google Scholar
Chupp, E. L.: 1984, Ann. Rev. Astron. Astrophys. 22, 359.CrossRefGoogle Scholar
Datlowe, D. W., Elcan, M. J., and Hudson, H. S.: 1974, Solar Phys. 39, 127.CrossRefGoogle Scholar
Decker, R. B.: 1989, Space Sci Rev. (in press).Google Scholar
Decker, R. D. and Vlahos, L.: 1986, Astrophys. J. 306, 710.Google Scholar
De Jager, G.: 1986, Space Sci. Rev. 44, 43.Google Scholar
De Jager, and De Jonge, G.: 1978, Solar Phys. 58, 127.Google Scholar
Dröge, F.: 1977, Astron. Astrophys. 57, 285.Google Scholar
Forrest, D. J. and Chupp, E. L.: 1983, Nature 305, 291.Google Scholar
Forman, M. A., Ramaty, R., and Zweibel, E. G.: 1985, in Sturrock, P. A. (ed.), The Physics of the Sun, D. Reidei Pubi. Co., Dordrecht, Holland, p. 249.CrossRefGoogle Scholar
Heyvaerts, J.: 1981, in Priest, E. R. (ed.), ‘Particle Acceleration in Solar Flares', Solar Flare Magnetohydro-dynamics, Gordon and Breach, New York, p. 429.Google Scholar
Holman, G.: 1985, Astrophys. J. 293, 584.Google Scholar
Holman, G., Kundu, M. R., and Eichler, : 1983, in Kundu, M. R. and Gergely, T. E. (eds.), ‘Radio Physics of the Sun', IAU Symp. 86, 457.Google Scholar
Hubbard, R. F. and Joyce, G.: 1979, J. Geophys. Res. 84, 4297.Google Scholar
Karimabadi, H., Menyuk, G R., Sprangle, P., and Vlahos, L.: 1987, Astrophys. J. 316, 462.Google Scholar
Kolomenskii, A. A. and Lebedev, A. N.: 1963, Soviet Phys. Dokl. 1, 745.Google Scholar
Kaufmann, P. et al: 1985, Solar Phys. 95, 155.Google Scholar
Lampe, M. and Papadopoulos, K.: 1977, Astrophys. J. 212, 886.Google Scholar
Lin, R. P., Schwartz, R. A., Kane, S. R., Pelling, R. M., and Harley, K. G.: 1983, Astrophys. J. 251, L109.Google Scholar
Low, B. G. and Wolfson, R.: 1988, Astrophys. J. 324, 574.Google Scholar
Martin, R. F.: 1986, J. Geophys. Res. 91, 11985.Google Scholar
Melrose, D. B.: 1983, Solar Phys. 89, 149.Google Scholar
Melrose, D. B. and Dulk, G. A.: 1982, Astrophys. J. 259, 844.Google Scholar
Moffat, H. K., 1987, in Comte-Bellot, G. and Mathieu, J. (eds.), Advances in Turbulence, Springer-Verlag, p. 240.Google Scholar
Moghaddam-Taaheri, E. and Vlahos, L.: 1987, Phys. Fluids 30, 3155.Google Scholar
Moghaddam-Taaheri, E., Vlahos, L., Rowland, H. L., and Papadopoulos, K.: 1985, Phys. Fluids 28, 3034.Google Scholar
Parker, E.: 1972, Astrophys. J. 174, 499.Google Scholar
Parker, E.: 1988, Astrophys. J. 330, 474.Google Scholar
Ramaty, R. and Murphy, R. J.: 1987, Space Sci. Rev. 45, 213.Google Scholar
Roberts, G S. and Buchsbaum, S. J.: 1964, Phys. Rev. A135, 381.Google Scholar
Sakai, Y. and Ohsawa, J.: 1987, Space Sci. Rev. 46, 113.Google Scholar
Sharma, R. R., Vlahos, L., and Papadopoulos, K.: 1982, Astron. Astrophys. 112, 377.Google Scholar
Scholer, M.: 1988, in Havnes, O. et al. (eds.), Activity in Cool Star Envelopes, D. Reidei Pubi. Co., Dordrecht, Holland, p. 195.Google Scholar
Slottje, G.: 1978, Nature 275, 520.Google Scholar
Smith, D. F.: 1980, Solar Phys. 66, 135.Google Scholar
Smith, R., 1983, in Kundu, M. R. and Holman, G. (eds.), ‘Unstable Current Systems and Instabilities in Astrophysics', IAU Symp. 107, 113.Google Scholar
Spicer, D. S.: 1983, Adv. Space Res. 2, 135.Google Scholar
Sprangle, and Vlahos, L.: 1983, Astrophys. J. 273, L95.Google Scholar
Steinolfson, R. S. and Van Hoven, G.: 1984, Astrophys. J. 276, 391.Google Scholar
Toptyghin, I. N.: 1980, Space Sci Rev. 26, 157.Google Scholar
Tverskoi, B. A.: 1967, Soviet Phys. JEPT 25, 317.Google Scholar
Van Hoven, G.: 1979, Astrophys. J. 232, 572.Google Scholar
Van Hoven, G., Tachi, T., and Steinolfson, R. S.: 1984, Astrophys. J. 280, 391.Google Scholar
Vlahos, L., Sharma, R. R., and Papadopoulos, K.: 1983, Astrophys. J. 275, 374.Google Scholar
Vlahos, L. et al: 1986, Energetic Phenomena on the Sun, NASA CP-2439, p. 2-1.Google Scholar
Winglee, R. M., Pritchett, P. L., and Dulk, G. A.: 1988, Astrophys. J. 327, 968.Google Scholar