Abstract
Gamma-ray observations are discussed to determine the density of protons of about 1 MeV precipitating to the photosphere. It is shown that Coulomb collisions will produce a positive slope in the proton distribution for energies less than 0.1 MeV for traversed column depths greater than 1018 cm −2. This could lead to plasma wave emission and radiation near the plasma frequency for densities ∼ 3.1 × 1010 cm−3 and temperatures ∼ 4.0 × 104 K where collisional and collisionless damping of the plasma waves is sufficiently weak. It is expected that these conditions will only be satisfied sporadically which leads to stationary radio emission limited in frequency and time. Recent radio observations of impulsive phase non-drifting patches in the 1–3 GHz range with duration 2–4 s are presented which could be produced by this mechanism.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Basri, G. S., Linsky, J. L., Bartol, J.-D. F., Brueckner, G., and van Hossier, M. E.: 1979, Astrophys. J. 230, 944.
Benz, A. O., Güdel, M., Isliker, H., Miszkowicz, S., and Stehling, W.: 1991, Solar Phys. (submitted).
Bruggmann, G., Benz, A. O., Magun, A., and Stehling, W.: 1990, Astron. Astrophys. (submitted).
Chupp, E. L.: 1984, Ann. Rev. Astron. Astrophys. 22, 359.
Chupp, E. L.: 1987, Phys. Scripta T18, 5.
Emslie, A. G.: 1978, Astrophys. J. 224, 241.
Emslie, A. G. and Smith, D. F.: 1984, Astrophys. J. 279, 882.
Galeev, A. A., Sagdeev, R. Z., Shapiro, V. D., and Shevchenko, V. I.: 1977, Soviet Phys.-JETP 46, 711.
Hua, X.-M. and Lingenfelter, R. E.: 1987, Solar Phys. 107, 351.
Hénoux, J. C., Chambe, G., Smith, D. et al.: 1990, Astrophys. J. Suppl. 93, 303.
Krall, N. A. and Trivelpiece, A. W.: 1973, Principles of Plasma Physics, McGraw-Hill, New York.
Kundu, M. R.: 1965, Solar Radio Astronomy, Wiley Interscience, New York.
Lang, K. R.: 1974, Astrophysical Formulae, Springer-Verlag, Berlin.
Lantos, P.: 1972, Solar Phys. 22, 387.
Machado, M. E., Avrett, E. H., Vernazza, J. E., and Noyes, R. W.: 1980, Astrophys. J. 242, 336.
McClements, K. G.: 1989, Astron. Astrophys. 208, 275.
Melrose, D. B.: 1980, Plasma Astrophysics, Vol. II, Gordon and Breach, New York.
Ramaty, R.: 1986, in P. A. Sturrock (ed.), Physics of the Sun, Vol. II, D. Reidel Publ. Co., Dordrecht, Holland, p. 291.
Ramaty, R. and Murphy, R. J.: 1987, Space Sci. Rev. 45, 213.
Schmidt, G.: 1966, Physics of High Temperature Plasmas, Academic Press, New York.
Smith, D. F.: 1974, Space Sci. Rev. 16, 91.
Smith, D. F., Chambe, G., Hénoux, J. C., and Tamres, D.: 1990, Astrophys. J. 358, 674.
Spitzer, L.: 1962, Physics of Fully Ionized Gases, 2nd ed., Interscience, New York.
Vernazza, J. E., Avrett, E. H., and Loeser, R.: 1981, Astrophys. J. Suppl. 45, 635.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Smith, D.F., Benz, A.O. A mechanism for producing plasma radiation in the gigahertz range by precipitating high-energy protons. Sol Phys 131, 351–361 (1991). https://doi.org/10.1007/BF00151643
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00151643