Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-26T22:37:12.451Z Has data issue: false hasContentIssue false
  • English
  • Français

East-West Asymmetry of Magnetic Bottle Expansion and Its Relation to Shock Waves Propagating in the Solar Atmosphere

Published online by Cambridge University Press:  25 May 2016

Kunitomo Sakurai
Kunitomo Sakurai*
Affiliation:
Radio Astronomy Branch, Laboratory for Extraterrestrial Physics, NASA, Goddard Space Flight Center, Greenbelt, Md., U.S.A.

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.

(Solar Phys.). It is known that the sources of metric type IV radio bursts generally move outwards with speed of a few to several hundred km s−1 in the solar atmosphere and envelope (e.g., Kundu, 1965; Smerd and Dulk, 1971; Wild and Smerd, 1972). These sources consist of magnetic lines of force being stretched out from the flare regions and relativistic electrons being trapped by these field lines. They are often observed as expanding magnetic bottles (e.g., Smerd and Dulk, 1971). As a result of this expanding motion, the frequency range of type IV burst extends with time to lower frequencies, because of the decrease of both magnetic field intensity and energy of radiating electrons (Dulk, 1970; Sakurai, 1973a). By considering the observed expansion rate of emission frequency range, it seems possible to estimate the pattern of expansion of these radio sources: in doing so, we have analyzed the onset time differences between microwave and metric emissions of type IV bursts by referring to the longitudinal positions of parent solar flares on the solar disk, since the dependence of these differences on parent flare positions in the solar longitude seems to give a clue to estimate a general pattern of the expansion of magnetic bottles. The result thus analyzed is shown in Figure 1. Furthermore, peak flux intensities at metric frequencies for these type IV bursts have been also analyzed as a function of the longitude positions of parent flares (Figure 2). The results shown in Figures 1 and 2 are explained by assuming that, while moving outwards, the magnetic bottle tends to expand a few 10 deg east of the meridian plane which crosses the flare region (Sakurai, 1973a).

Type
Part III Shock Waves and Plasma Ejection
Information
Symposium - International Astronomical Union , Volume 57: Coronal Disturbances , 1974 , pp. 355 - 359
Copyright
Copyright © Reidel 1974 

References

Brandt, J. C.: 1966, Astrophys. J. 143, 205.Google Scholar
Burlaga, L. F.: 1974, NASA, GSFC Note X-692–72–395. Proceedings of Boulder Conf. on Shock Waves from the Sun, p. 123.Google Scholar
Dulk, G. A.: 1970, Proc. ASA 1, 372.Google Scholar
Dulk, G. A., Altschuler, M. D., and Smerd, S. F.: 1971, Astrophys. Letters 8, 235.Google Scholar
Hirshberg, J., Bame, S., and Robbins, D. E.: 1972, Solar Phys. 23, 487.CrossRefGoogle Scholar
Kai, K.: 1973, private communication.Google Scholar
Kundu, M. R.: 1965, Solar Radio Astronomy, Wiley, New York.Google Scholar
Nakada, M. P.: 1969, Solar Phys. 7, 302.Google Scholar
Nakada, M. P.: 1970, Solar Phys. 14, 457.CrossRefGoogle Scholar
Sakurai, K.: 1973a, Solar Phys. 31, 483.Google Scholar
Sakurai, K.: 1973b, Physics of Solar Cosmic Rays, Univ. of Tokyo Press, Tokyo.Google Scholar
Sakurai, K. and Chao, J. K.: 1974, J. Geophys. Res. 79, 661.Google Scholar
Smerd, S. F. and Dulk, G. A.: 1971, in Howard, R. (ed.), ‘Solar Magnetic Fields’, IAU Symp. 43, 616.Google Scholar
Wild, J. P. and Smerd, S. F.: 1972, Ann. Rev. Astron. Astrophys. 10, 159.CrossRefGoogle Scholar