Advertisement

Solar Physics

, Volume 221, Issue 1, pp 65–84 | Cite as

Three-Dimensional Structure of the Active Region Photosphere as Revealed by High Angular Resolution

  • B.W. Lites
  • G.B. Scharmer
  • T.E. Berger
  • A.M. Title
Article

Abstract

Blue continuum images of active regions at ∼ 60° from the center of the solar disk obtained with the new Swedish 1-m Solar Telescope reveal heretofore unreported structure of the magnetized solar atmosphere. Perhaps the most striking aspect of these images is that, at an angular resolution of 0.12″, they show clearly the three-dimensional structure of the photosphere. In particular, the Wilson depression of the dark floors of pores is readily apparent. Conversely, the segmented structure of light bridges running through sunspots and pores reveal that light bridges are raised above the dark surroundings. The geometry of light bridges permits estimates of the height of their central (slightly darker) ridge: typically in the range 200–450 km. These images also clearly show that facular brightenings outside of sunspots and pores occur on the disk-center side of those granules just limbward of intergranular lanes that presumably harbor the associated plage magnetic flux. In many cases the brightening extends 0.5″ or more over those granules. Furthermore, a very thin, darker lane is often found just centerward of the facular brightening. We speculate that this feature is the signature of cool down flows that surround flux tubes in dynamical models. These newly recognized observational aspects of photospheric magnetic fields should provide valuable constraints for MHD models of the magnetized photosphere, and examination of those models as viewed from oblique angles is encouraged.

Keywords

Angular Resolution Flux Tube Solar Atmosphere Solar Disk High Angular Resolution 
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.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Auffret, H. and Muller, R.: 1981, Astron. Astrophys. 246, 264.ADSGoogle Scholar
  2. Berger, T. E., and Berdyugina, S. V.: 2003, Astrophys. J. 589, L117.CrossRefADSGoogle Scholar
  3. Berger, T. E., Schrijver, C. J., Shine, R. A., Tarbell, T. D., Title, A. M., and Scharmer, G.: 1995, Astrophys. J. 454, 531.CrossRefADSGoogle Scholar
  4. Bellot Rubio, L. R., Ruiz Cobo, B., and Collados, M.: 2000, Astrophys. J. 535, 489.ADSGoogle Scholar
  5. Brault, J. W. and White, O. R.: 1971, Astron. Astrophys. 13, 169.ADSGoogle Scholar
  6. Dunn, R. B. and Zirker, J. B.: 1973, Solar Phys. 33, 281.ADSGoogle Scholar
  7. Fabiani Bendicho, P., Kneer, F., and Trujillo Bueno, J.: 1992, Astron. Astrophys. 264, 229.ADSGoogle Scholar
  8. Frutiger, C. and Solanki, S. K.: 2001, Astron. Astrophys. 369, 646.CrossRefADSGoogle Scholar
  9. García de la Rosa: 1987, Solar Phys. 112, 49.ADSGoogle Scholar
  10. Keller, C. U.: 1992, Nature 359, 307.CrossRefADSGoogle Scholar
  11. Leka, K. D.: 1997, Astrophys. J. 484, 900.CrossRefADSGoogle Scholar
  12. Lites, B. W.: 2000, Rev. Geophys. 38, 1.CrossRefADSGoogle Scholar
  13. Lites, B. W., Bida, T. A., Johannesson, A., and Scharmer, G. B.: 1991, Astrophys. J. 373, 683.CrossRefADSGoogle Scholar
  14. Lites, B.W., Elmore, D. F., Streander, K. V., Sankarasubramanian, K., Rimmele, T. R., and Sigwarth, M.: 2003, in J. Trujillo Bueno and J. Sánchez Almeida (eds.), Proceedings, Third International Workshop on Solar Polarization, Conference Series (in press).Google Scholar
  15. Moore, R. L.: 1981, Astrophys. J. 249, 390.CrossRefADSGoogle Scholar
  16. Nordlund, Å.: 2003, private communication.Google Scholar
  17. Rouppe van der Voort, L. H. M., Löfdahl, M. G., Kiselmann, D., and Scharmer, G. B.: 2003, Astron. Astrophys. (in press).Google Scholar
  18. Scharmer, G. B., Bjelksjö, K., Korhonen, T., Lindberg, B., and Petterson, B.: 2003a, in S. Keil and S. Avakyan (eds.), Innovative Telescopes and Instrumentation for Solar Astrophysics, SPIE Proceedings Series 4853-47, Bellingham, Washington, p. 341.Google Scholar
  19. Scharmer, G. B., Dettori, P., Löfdahl, M. G., and Shand, M.: 2003b, in S. Keil and S. Avakyan (eds.), Innovative Telescopes and Instrumentation for Solar Astrophysics, SPIE Proceedings Series 4853-47, Bellingham, Washington, p. 370.Google Scholar
  20. Scharmer, G. B., Gudiksen, B. V., Kiselman, D., Löfdahl, M. G., and Rouppe van der Voort, L. H. M.: 2002c, Nature 420, 151.CrossRefADSGoogle Scholar
  21. Spruit, H. C.: 1977, Solar Phys., 55, 3.CrossRefADSGoogle Scholar
  22. Spruit, H. C.: 1987, in E. H. Schröter, M. Vázquez, and A. A. Wyller (eds.), The Role of Fine-Scale Magnetic Fields on the Structure of the Solar Atmosphere, Cambridge University Press, Cambridge, p. 199.Google Scholar
  23. Spruit, H. C. and Zwaan, C,: 1981, Solar Phys., 70, 207.CrossRefADSGoogle Scholar
  24. Steiner, O.: 2003, private communication.Google Scholar
  25. Steiner, O., Grossmann-Doerth, U., Knölker, M., and Schüssler, M.: 1998, Astrophys. J. 495, 468.CrossRefADSGoogle Scholar
  26. Stix, M.: 1989, The Sun: An Introduction, Springer-Verlag, Berlin, p. 290.Google Scholar
  27. Title, A. M., Topka, K. P., Tarbell, T. D., Schmidt, W., Balke, C., and Scharmer, G. B.: 1992, Astrophys. J. 393, 782.CrossRefADSGoogle Scholar
  28. Topka, K. P., Tarbell, T. D., and Title, A. M.: 1997, Astrophys. J. 484, 479.CrossRefADSGoogle Scholar
  29. van Ballegooijen, A. A., Nisenson, P., Noyes,. R. W., Löfdahl, M. G., Stein, R. F., Nordlund, Å, and Krishnakkumar, V.: 1998, Astrophys. J. 509, 435.CrossRefADSGoogle Scholar

Copyright information

© Kluwer Academic Publishers 2004

Authors and Affiliations

  • B.W. Lites
    • 1
  • G.B. Scharmer
    • 2
  • T.E. Berger
    • 3
  • A.M. Title
    • 3
  1. 1.High Altitude Observatory, National Center for Atmospheric ResearchBoulderU.S.A.
  2. 2.Institute for Solar Physics of the Royal Swedish Academy of SciencesAlbaNova University CenterStockholmSweden
  3. 3.Lockheed Martin Solar and Astrophysics LaboratoryPalo AltoU.S.A.

Personalised recommendations