Abstract
The projected source positions at 43, 80, and 160 MHz and the sense and degree of circular polarization in the range 24 to 220 MHz, as observed with the Culgoora radioheliograph and spectropolarimeter respectively, are used:
-
(1)
To substantiate the hypothesis that metric U bursts originate in high coronal, magnetic loops.
-
(2)
To strengthen the hypothesis that U-burst radiation is in the ordinary magneto-ionic mode.
The occasional observation of different senses of circular polarization on either side of the turning point of a U burst suggests that U-burst radiation in these cases reaches its limiting polarization at or near the source. This observation raises the same difficulties as those discussed by Melrose (1973) in connection with the bi-polar nature of type-I storm sources.
Similar content being viewed by others
References
Benz, A. O., Berney, M., and Santon, P.: 1977, Astron. Astrophys. 56, 123.
Daene, H., Scholz, D., and Voigt, W.: 1970, Heinrich-Hertz-Inst. Suppl. Ser. Solar Data II (2), 131.
Fainberg, J., Evans, L. G., and Stone, R. G.: 1972, Science 178, 743.
Gosling, J. T., Hildner, E., MacQueen, R. M., Munro, R. H., Poland, A. E., and Ross, C. L.: 1974, J. Geophys. Res. 79, 458.
Gurnett, A. D. and Anderson, R. R.: 1976, Science 194, 1159.
Labrum, N. R. and Stewart, R. T.: 1970, Proc. Astron. Soc. Australia 1, 316.
Lin, R. P.: 1970, Solar Phys. 12, 266.
Melrose, D. B.: 1973, Proc. Astron. Soc. Australia 2, 208.
Sheridan, K. V.: 1967, Proc. Astron. Soc. Australia 1, 58.
Sheridan, K. V., McLean, D. J., and Smerd, S. F.: 1973, Astrophys. Letters 15, 139.
Stewart, R. T. and Vorpahl, J.: 1977, Solar Phys. 55, 111.
Suzuki, S.: 1974, Solar Phys. 38, 3.
Suzuki, S. and Sheridan, K. V.: 1977, Izv. Vyssh. Uchebn. Zaved. Radiofiz. XX(9), 1432.
Wild, J. P. (ed.): 1967, Proc. Inst. Radio Electron. Eng. (Australia) 28, 277.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Suzuki, S. On the coronal source regions of U bursts. Sol Phys 57, 415–422 (1978). https://doi.org/10.1007/BF00160114
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00160114