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Solar Physics

, Volume 151, Issue 1, pp 75–89 | Cite as

Dynamical fine structure of a quiescent filament

  • N. Mein
  • P. Mein
  • J. E. Wiik
Article

Abstract

A quiescent filament was observed near the center of the disk (N5, W5) with the MSDP spectrograph of the 50 cm refractor of the Pic-du-Midi Observatory on June 17, 1986. We focus our study on the statistical moments of the Dopplershift,V 1, and the intensity,I 1, at the center of a chord of the Hα profile (±0.256 Å), versus the minimum intensityI 0. We use a statistical model simulating a numbern max of threads (of optical thicknessτ 0 and source functionS 0), seen over the chromosphere. The threadsj along the same line-of-sighti are identical except for the velocityv j (gaussian distributionv 0,σ v). We search for the best fit between the observed and simulated quantities:V 1,σ (V 1),I 1,σ(I 1), and the histogram of theI 0 values over the field of view. A good fit is obtained with: (a) threads characterized byτ 0 = 0.2,S 0 = 0.06 (unit of the continuum at disk center), mean upward velocityv 0 = 1.7 km s−1 and gaussian-type velocity distributionσ v = 3.5 km s−1. Other possible values ofτ 0 andσ v are discussed; (b) underlying chromosphere deduced from observed quiet Sun (outside the filament) by modifying the chromospheric velocities: additional mean upward velocity 0.7 km s−1, standard deviation reduced by a factorF c ∼ 0.7. The results are discussed in connection with the values deduced from prominence observations.

Keywords

Solar Phys Optical Thickness Source Function Disk Center Upward Velocity 
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. David, K. H.: 1961,Z Astrophys. 53, 37.ADSGoogle Scholar
  2. Darvann, T. A., Koutchmy, S., and Zirker, J. B.: 1989,Hvar Obs. Bull. 13, 243.ADSGoogle Scholar
  3. Engvold, O. and Keil, S. I.: 1986, in A. I. Poland (ed.),Coronal and Prominence Plasmas, NASA Conference Publ. 2442, p. 169.Google Scholar
  4. Engvold, O., Jensen, E., Yi Zhang, and Brynnildsen, N.: 1989,Hvar Obs. Bull. 13, 205.ADSGoogle Scholar
  5. Gouttebroze, P., Heinzel, P., and Vial, J. C.: 1993,Astron. Astrophys. Suppl Ser. 99, 513.ADSGoogle Scholar
  6. Malherbe, J. M.: 1987, Thèse Université Paris VII.Google Scholar
  7. Malherbe, J. M., Schmieder, B., Ribes, E., and Mein, P.: 1983,Astron. Astrophys. 119, 197.ADSGoogle Scholar
  8. Martin, S.: 1990,Proceedings of the IAU Colloq. 117,Lecture Notes in Physics 363, 1.ADSCrossRefGoogle Scholar
  9. Martres, M. J., Mein, P., Schmieder, B., and Soru-Escaut, I.: 1981,Solar Phys. 69, 301.CrossRefADSGoogle Scholar
  10. Mein, P.: 1991,Astron. Astrophys. 248, 669.ADSGoogle Scholar
  11. Mein, P. and Mein, N.: 1991,Solar Phys. 136, 317 (Paper I).CrossRefADSGoogle Scholar
  12. Roudier, Th., Mein, P., Muller, R., Vigneau, J., Malherbe, J. M., Coutard, C., and Hellier, R.: 1991,Astron. Astrophys. 248, 237.ADSGoogle Scholar
  13. Schmieder, B.: 1989, in E. Priest (ed.),Dynamics and Structure of Quiet Solar Prominences, Kluwer Academic Publishers, Dordrecht, Holland, p. 15.Google Scholar
  14. Schmieder, B.: 1992,Solar Phys. 141, 275.CrossRefADSGoogle Scholar
  15. Schmieder, B., Raadu, M. A., and Wiik, J. E.: 1991,Astron. Astrophys. 252, 353.ADSGoogle Scholar
  16. Vial, J. C., Rovira, M., Fontenla, J., and Gouttebroze, P.: 1989,Hvar Obs. Bull. 13, 347.ADSGoogle Scholar
  17. Wiik, J. E., Heinzel, P., and Schmieder, B.: 1992,Astron Astrophys. 260, 419.ADSGoogle Scholar
  18. Yi Zhang and Engvold, O.: 1991,Solar Phys. 134, 275.CrossRefADSGoogle Scholar
  19. Yi Zhang, Engvold, O., and Keil, S. L.: 1991,Solar Phys. 132, 63.CrossRefADSGoogle Scholar
  20. Zirker, J. B. and Koutchmy, S.: 1990,Solar Phys. 127, 109.CrossRefADSGoogle Scholar
  21. Zirker, J. B. and Koutchmy, S.: 1991,Solar Phys. 131, 107.CrossRefADSGoogle Scholar

Copyright information

© Kluwer Academic Publishers 1994

Authors and Affiliations

  • N. Mein
    • 1
  • P. Mein
    • 1
  • J. E. Wiik
    • 1
  1. 1.Observatoire de ParisDASOP, URA326Meudon Principal CedexFrance

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