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Solar Physics

, Volume 160, Issue 1, pp 151–169 | Cite as

Location of type I radio continuum and bursts on Yohkoh soft X-ray maps

  • S. Krucker
  • A. O. Benz
  • M. J. Aschwanden
  • T. S. Bastian
Article

Abstract

A solar type I noise storm was observed on 30 July, 1992 with the radio spectrometer Phoenix of ETH Zürich, the Very Large Array (VLA) and the soft X-ray (SXR) telescope on board theYohkoh satellite. The spectrogram was used to identify the type I noise storm. In the VLA images at 333 MHz a fully left circular polarized (100% LCP) continuum source and several highly polarized (70% to 100% LCP) burst sources have been located. The continuum and the bursts are spatially separated by about 100″ and apparently lie on different loops as outlined by the SXR. Continuum and bursts are separated in the perpendicular direction to the magnetic field configuration. Between the periods of strong burst activities, burst-like emissions are also superimposed on the continuum source. There is no obvious correlation between the flux density of the continuum and the bursts. The burst sources have no systematic motion, whereas the the continuum source shows a small drift of ≈ 0.2″ min−1 along the X-ray loop in the long-time evolution. The VLA maps at higher frequency (1446 MHz) show no source corresponding to the type I event. The soft X-ray emission measure and temperature were calculated. The type I continuum source is located (in projection) in a region with enhanced SXR emission, a loop having a mean density of 〈ne〉 = (1.5 ± 0.4) × 109 cm−3 and a temperature ofT = (2.1 ± 0.1) × 106 K. The centroid positions of the left and right circularly polarized components of the burst sources are separated by 15″–50″ and seem to be on different loops. These observations contradict the predictions of existing type I theories.

Keywords

Emission Measure Burst Activity Continuum Source Centroid Position Magnetic Field Configuration 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Benz, A. O.: 1993,Plasma Astrophysics, Kluwer Academic Publishers, Dordrecht, Holland.Google Scholar
  2. Benz, A. O. and Wentzel, D. G.: 1981,Astron. Astrophys. 84, 100.Google Scholar
  3. Benz, A. O., Jaeggi, M., Mosher, J. M., and Nelson, G. J.:, 1984,Orages Solaires de Type 1, Edition du CNRS, p. 148.Google Scholar
  4. Benz, A. O., Güdel, M., Isliker, H., Miszkowicz, S., and Stehling, W.: 1991,Solar Phys. 133, 385.Google Scholar
  5. Clark, B. G.: 1980,Astron. Astrophys. 89, 377.Google Scholar
  6. Cornwell, T. and Fomalont, E.: 1989,Astr Soc. Pac. Conference Ser. 6, 185.Google Scholar
  7. Daigne, G.: 1968,Nature 220, 567.Google Scholar
  8. Elgarøy, O.:, 1977,Solar Noise Storms, Pergamon Press, Oxford, U.K.Google Scholar
  9. Habbal, S. R. Ellman, N. E., and Gonzalez, R.: 1989,Astrophys. J. 342, 594.Google Scholar
  10. Hara, H., Tsuneta, S., Lemen, J. R., Acton, L. W., and McTiernan, J. M.: 1992,Astron. Soc. Japan 44, L135.Google Scholar
  11. Kai, K.: 1970,Solar Phys. 11, 456.Google Scholar
  12. Kai, K., Melrose, D. B., and Suzuki, S.: 1985, in D. J. McLean and N. R. Labrum (eds.),Solar Radiophysics, Cambridge University Press, Cambridge, U.K.Google Scholar
  13. Kerdraon, A.: 1979,Astron. Astrophys. 71, 266.Google Scholar
  14. Kundu, M. R. and Gopalswamy, N.: 1990,Solar Phys. 129, 133.Google Scholar
  15. Lang, K. R. and Willson, R. T.:, 1987,Astrophys. J. 319, 514.Google Scholar
  16. Lantos, P., Kerdraon, A., Rapley, G. G., and Bentley, R. D.: 1981,Astron. Astrophys. 101, 33.Google Scholar
  17. McTiernan, J. M., Kane, S. R., Loren, J. M., Lemen, J. R., Acton, L. W., Hara, H., Tsuneta, S., and Kosugi, T.: 1993,Astrophys. J. 416, L91.Google Scholar
  18. Pearson, T. J. and Readhead, A. C.: 1984,Ann. Rev. Astron. Astrophys. 22, 97.Google Scholar
  19. Raulin, J. P. and Klein, K.-L.: 1994,Astron. Astrophys. 281, 536.Google Scholar
  20. Raulin, J. P., Willson, R. F., Kerdraon, A., Klein, K.-L., Lang, K. R., and Trottet, G.: 1993,Astron. Astrophys. 251, 295.Google Scholar
  21. Sakurai, T: 1982,Solar Phys. 76, 301.Google Scholar
  22. Spicer, D. S., Benz, A. O., and Huba, J. D.: 1981,Astron. Astrophys. 105, 221.Google Scholar
  23. Stewart, R. T., Brueckner, G. E., and Dere, K. P.: 1986,Solar Phys. 94, 100.Google Scholar
  24. Suzuki, S.: 1961,Ann. Tokyo Astron. Obs. 7, 75.Google Scholar
  25. Tsuneta, S., Acton, L., Bruner, M., Lemen, J., Brown, W., Carvalho, R., Catura, R., Freeland, S., Jurchevich, B., Morrison, M., Ogawara, Y., Hirayama, T., and Owens, J.: 1991,Solar Phys. 136, 37.Google Scholar
  26. van Nieuwkoop, J.: 1986,Solar Phys. 103, 129.Google Scholar
  27. Wentzel, D. G.: 1981,Astron. Astrophys. 100, 20.Google Scholar
  28. White, S. M., Thejappa, G., and Kundu, M. R.: 1992,Solar Phys. 138, 163.Google Scholar
  29. Willson, R. F., Lang, K. R., and Liggett, M.: 1990,Astrophys. J. 350, 856.Google Scholar

Copyright information

© Kluwer Academic Publishers 1995

Authors and Affiliations

  • S. Krucker
    • 1
  • A. O. Benz
    • 1
  • M. J. Aschwanden
    • 2
  • T. S. Bastian
    • 3
  1. 1.Institute of AstronomyZurichSwitzerland
  2. 2.Department of AstronomyUniversity of MarylandCollege ParkUSA
  3. 3.National Radio Astronomy ObservatorySocorroUSA

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