Hostname: page-component-5c6d5d7d68-wp2c8 Total loading time: 0 Render date: 2024-08-18T23:22:25.201Z Has data issue: false hasContentIssue false
  • English
  • Français

Radio Evidence for Nonthermal Particle Acceleration on Stars of Late Spectral Type

Published online by Cambridge University Press:  12 April 2016

Kenneth R. Lang
Kenneth R. Lang*
Affiliation:
Department of Physics and Astronomy, Tufts University, Medford, MA 02155

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.

Radio evidence for nonthermal particle acceleration on stars of late spectral type (G, K, and M) is reviewed, including the pre-main-sequence T Tauri stars, the dwarf M flare stars, and the RS CVn binary stars. Both the long-lasting radio emission and the transient radio flares can be attributed to nonthermal electrons accelerated in magnetically confined coronae, radiating by either incoherent gyrosynchrotron radiation or by coherent processes. Related observations of the Sun provide the framework for interpreting the radio emission of late-type stars. We review recent VLBI observations of single and binary stars, observations of rapid acceleration and dynamic spectra of dwarf M flare stars, and models for long-lasting radio emission from dwarf M flare stars and RS CVn stars. The VLBI data provide evidence for nonthermal particle acceleration in large-scale magneto-spheres several times larger than the stellar radius for T Tauri and RS CVn stars. In contrast, rapid radio flares on dwarf M stars require sources much smaller than the visible star in size, and this is consistent with the VLBI data.

Dynamic spectra suggest particle acceleration by relativistic electron beams on dwarf M stars. The long-lived radio radiation of dwarf M stars and RS CVn stars requires more-or-less continuous particle acceleration over periods of hours, perhaps by persistent low-amplitude flaring.

Subject headings: acceleration of particles — binaries: close — radio continuum: stars — stars: flare — stars: late-type — stars: pre-main-sequence

Type
Stars
Information
International Astronomical Union Colloquium , Volume 142: Particle Acceleration Phenomena in Astrophysical Plasmas , 1994 , pp. 753 - 764
Copyright
Copyright © The American Astronomical Society 1994

References

Akhmedov, Sh. B., et al. 1986, ApJ, 301, 460 Google Scholar
Alef, W., Benz, A.O., Güdel, M., & de Vicente, P. 1993, in preparationGoogle Scholar
Alissandrakis, C.E., & Kundu, M.R. 1982, ApJ, 253, L49 Google Scholar
André, P., Deeney, B.D., Phillips, R.B., & Lestrade, J.-F. 1992, ApJ, 401, 667 Google Scholar
André, P., Montmerle, T., & Feigelson, E.D. 1987, AJ, 93, 1182 Google Scholar
André, P., Phillips, R.B., Lestrade, J.-F., & Klein, K.-L. 1991, ApJ, 376, 630 Google Scholar
Bastian, T.S. 1990, Sol. Phys., 130, 265 CrossRefGoogle Scholar
Bastian, T.S., & Bookbinder, J.A. 1987, Nature 326, 678 CrossRefGoogle Scholar
Bastian, T.S., Bookbinder, J., Dulk, G.A., & Davis, M. 1990, ApJ 353, 265 Google Scholar
Benz, A.O., & Alef, W. 1991, A&A, 252, L19 Google Scholar
Benz, A.O., Gudel, M., Bastian, T.S., Furst, E., Simnett, G.M., & Pointon, L. 1990, in 1AU Symp. 137, Flare Stars in Star Clusters, Associations, and the Solar Vicinity, ed. Mirzoyan, L.V. et al. (Dordrecht: Kluwer), 139 Google Scholar
Benz, A.O., & Kuijpers, J. 1976, Sol. Phys., 46, 475 Google Scholar
Bogod, V.M., Gelfreikh, G.B., Willson, R.F., Lang, K.R., Opeikina, L.V., Shatilov, V., & Tsvetkov, S.V. 1992, Sol. Phys., 141, 303 CrossRefGoogle Scholar
Bookbinder, J.A., et al. 1992, S&T, 83, 625 Google Scholar
Brown, R.L., & Crane, P.C. 1979, AJ 83, 1504 Google Scholar
Clark, T.A., et al. 1976 ApJ, 206, L107 CrossRefGoogle Scholar
Drake, S.A., Simon, T., & Linsky, J.L. 1989, ApJS, 71, 905 CrossRefGoogle Scholar
Drake, S.A., Simon, T., & Linsky, J.L. 1992, ApJS, 82, 311 Google Scholar
Fiegelson, E.D., Giampapa, M.S., & Vrba, F.J. 1991, in The Sun in Time, ed. Sonett, C.P., Giampapa, M.S., & Matthews, M.S. (Tucson: Univ. Arizona Press), 658 Google Scholar
Gary, D.E., Linsky, J.L., & Dulk, G.A. 1982, ApJ, 263, L69 Google Scholar
Güdel, M. 1992, A&A, 264, L31 Google Scholar
Güdel, M., & Benz, A.O. 1989, A&A, 211, L5 Google Scholar
Güdel, M., & Benz, A.O. 1993, ApJ, 405, L63 CrossRefGoogle Scholar
Güdel, M., Benz, A.O., Bastian, T.S., Furst, E., Simnett, G.M., & Davis, R.J. 1989, A&A, 220, L5 Google Scholar
Güdel, M., et al. 1993, in preparationGoogle Scholar
Haisch, B., Strong, K.T., & Rodono, M. 1991, ARA&A, 29, 275 Google Scholar
Hjellming, R.M. 1988, in Galactic and Extragalactic Radio Astronomy, ed. Verschuur, G.L. & Kellermann, K.I. (New York: Springer), 381 CrossRefGoogle Scholar
Jackson, P.D., Kundu, M.R., & White, S.M. 1987, ApJ, 316, L85 Google Scholar
Jackson, P.D., Kundu, M.R., & White, S.M. 1989, A&A, 210, 284 Google Scholar
Klein, K.-L., & Chiuderi-Drago, F. 1987, A&A, 175, 179 Google Scholar
Kuijpers, J., 1989, Sol. Phys., 121, 163 CrossRefGoogle Scholar
Kundu, M.R., Jackson, P.D., White, S.M., & Melozzi, M. 1987, ApJ, 312, 822 Google Scholar
Kundu, M.R., & Lang, K.R. 1985, Science, 228, 9 Google Scholar
Kundu, M.R., Schmahl, E.J., Velusamy, T., & Vlahos, L. 1982, A&A, 108, 188 Google Scholar
Kundu, M.R., & Shevgaonkar, R.K. 1985, ApJ, 297, 644 CrossRefGoogle Scholar
Kundu, M.R., & Shevgaonkar, R.K. 1988, ApJ, 334, 1001 Google Scholar
Lang, K.R. 1986, Adv. Space Res., 6, No. 8, 109 Google Scholar
Lang, K.R. 1990a, in IAU Symp. 142, Basic Plasma Processes on the Sun, ed. Priest, E.R. & Krishan, V. (Dordrecht: Kluwer), 501 Google Scholar
Lang, K.R. 1990b, in IAU Symp. 137, Flare Stars in Star Clusters, Associations and the Solar Vicinity, ed. Mirzoyan, L.V. et al. (Dordrecht: Kluwer), 125 CrossRefGoogle Scholar
Lang, K.R. 1991, Astrophysical Data: Planets and Stars (New York: Springer)Google Scholar
Lang, K.R., Bookbinder, J., Golub, L., & Davis, M.M. 1983, ApJ, 272, L15 Google Scholar
Lang, K.R., & Willson, R.F. 1982, ApJ, 255, Ll11 CrossRefGoogle Scholar
Lang, K.R., & Willson, R.F. 1986a, Adv. Space Res., 6, No. 6, 97 Google Scholar
Lang, K.R., & Willson, R.F. 1986b, ApJ, 305, 363 Google Scholar
Lang, K.R., & Willson, R.F. 1986c, ApJ, 302, L17 Google Scholar
Lang, K.R., & Willson, R.F. 1988, ApJ, 326, 300 CrossRefGoogle Scholar
Lang, K.R., et al. 1993, ApJ, in pressGoogle Scholar
Lang, K.R., Willson, R.F., Smith, K.L., & Strong, K.T. 1987a, ApJ, 322, 1035 Google Scholar
Lang, K.R., Willson, R.F., Smith, K.L., & Strong, K.T. 1987b, ApJ, 322, 1044 CrossRefGoogle Scholar
Lestrade, J.-F. 1988, in IAU Symp. 129, in The Impact of VLBI on Astrophysics and Geophysics, ed. Reid, M.J. & Moran, J.M. (Dordrecht: Reidel), 265 Google Scholar
Lestrade, J.-F., Mutel, R.L., Preston, R.A., & Phillips, R.B. 1988, ApJ, 328, 232 Google Scholar
Lim, J., Nelson, G.J., Castro, C., Kilkenny, D., & van Wyk, F. 1992, ApJ, 388, L27 Google Scholar
McLean, D.J., & Labrum, N.R. 1985, Solar Radiophysics (New York: Cambridge Univ. Press)Google Scholar
Melrose, D.B., & Dulk, G.A. 1982, ApJ, 259, 844 Google Scholar
Morris, D.H., Mutel, R.L., & Shu, B. 1990, ApJ, 362, 299 Google Scholar
Mutel, R.L., Lestrade, J.-F., Preston, R.A., & Phillips, R.B. 1985, ApJ, 289, 262 Google Scholar
Mutel, R.L., Morris, D.H., Doiron, D.J., & Lestrade, J.-F. 1987, AJ, 93, 1220 Google Scholar
Owen, F.N., Jones, T., & Gibson, D. 1976, ApJ, 210, L27 Google Scholar
Pallavicini, R., Golub, L., Rosner, R., Vaiana, G.S., Ayres, T., & Linsky, J.L. 1981, ApJ, 248, 279 CrossRefGoogle Scholar
Pallavicini, R., Stella, L., & Tagliaferri, G. 1990, in IAU Symp. 137, Flare Stars in Star Clusters, Associations, and the Solar Vicinity, ed. Mirzoyan, L. V. et al. (Dordrecht: Kluwer), 147 CrossRefGoogle Scholar
Pallavicini, R., Willson, R.F., & Lang, K.R. 1985, A&A, 149, 95 Google Scholar
Parker, E.N. 1988, ApJ, 330, 474 Google Scholar
Phillips, R.B. 1992, in Cool Stars, Stellar Systems, and the Sun, ed. Giampapa, M. S. & Bookbinder, J.A. (ASP Conf. Ser., 26), 309 Google Scholar
Phillips, R.B., Lonsdale, C.J., & Feigelson, E.D. 1991, ApJ, 382, 261 CrossRefGoogle Scholar
Phillips, R.B., Lonsdale, C.J., & Feigelson, E.D. 1993, ApJ, 403, L43 Google Scholar
Roberts, B., Edwin, P.M., & Benz, A.O. 1984, ApJ, 279, 858 Google Scholar
Slee, O.B., & Stewart, R.T. 1989, MNRAS, 236, 129 Google Scholar
Stine, P.C., Feigelson, E.D., Andre, P., & Montmerle, T. 1988, AJ, 96, 1394 Google Scholar
Sturrock, P.A., Dixon, W.W., Klimchuk, J.A., & Antiochos, S.K. 1990, ApJ, 365, L31 Google Scholar
Uchida, V., & Sakurai, T. 1983, in IAU Colloq. 71, Activity in Red Dwarf Stars, ed. Rodono, M. & Byrne, P. (Dordrecht: Reidel), 629 CrossRefGoogle Scholar
White, S.M., Jackson, P.D., & Kundu, M.R. 1989a, ApJS, 71, 895 Google Scholar
White, S.M., Jackson, P.D., & Kundu, M.R. 1989b, A&A, 199, 255 Google Scholar
White, S.M., Kundu, M.R., & Jackson, P.D. 1986, ApJ, 311, 814 CrossRefGoogle Scholar
White, S.M., Pallavicini, R., & Kundu, M.R. 1992a, A&A, 259, 149 Google Scholar
White, S.M., Pallavicini, R., & Kundu, M.R. 1992b, A&A, 259, 149 Google Scholar
Willson, R.F., & Lang, K.R. 1987, ApJ, 312, 278 Google Scholar
Willson, R.F., Lang, K.R., & Liggett, M. 1990, ApJ, 350, 856 Google Scholar