Advertisement

Photospheric Magnetic Field at Small Scales

  • O. Steiner
Part of the NATO Science Series II: Mathematics, Physics and Chemistry book series (NAII, volume 124)

Abstract

Polarimetric measurements with high spatial resolution and in the near infrared spectral range show a continuous distribution of field strength from the weakest measurable to the thermal equipartition value. The shape of the distribution depends on the location at the solar surface, which is incompatible with the proposition of a universal probability density function for the magnetic field strength. This local dependence indicates that separate physical processes for intensifying the flux density act at the solar surface on distinct spatial and temporal scales. The true challenge, thus, consists in discovering the diverse physical processes that cause magnetic structuring. Three amplification mechanisms are reviewed and confronted with probability density functions derived from observations: The convective collapse, magnetoconvective flux intensification, and magnetic intensification by thermal relaxation. Magnetohydrodynamic simulations of the convective collapse predict a continuous distribution of weak field strengths with an additional distinct component of thermal equipartition energy not unlike that measured in the network. Simulations of the fast dynamo are more compatible with the distribution measured in the inter network.

Keywords

Probability Density Function Probability Density Function Solar Phys Solar Surface Thermal Relaxation 
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. Beckers, J. M. and E. H. Schröter: 1968, In: K. Kiepenheuer (ed.): IAU Symp. 35: Structure and Development of Solar Active Regions, Vol. 35. p. 178.Google Scholar
  2. Bellot Rubio, L. R., I.Rodríguez Hidalgo, M. Collados, E. Khomenko, and B. Ruiz Cobo: 2001, Astrophys. J. 560, 1010.ADSCrossRefGoogle Scholar
  3. Berger, T. E., M. G. Löfdahl, R. A. Shine, and A. M. Title: 1998a, Astrophys. J. 506, 439.Google Scholar
  4. Berger, T. E., M. G. Löfdahl, R. S. Shine, and A. M. Title: 1998b, Astrophys. J. 495, 973.ADSCrossRefGoogle Scholar
  5. Berger, T. E., C. J. Schrijver, R. A. Shine, T. D. Tarbell, A. M. Title, and G. Scharmer: 1995, Astrophys. J. 454, 531.ADSCrossRefGoogle Scholar
  6. Berger, T. E. and A. M. Title: 1996, Astrophys. J. 463, 365.ADSCrossRefGoogle Scholar
  7. Berger, T. E. and A. M. Title: 2001, Astrophys. J. 553, 449.ADSCrossRefGoogle Scholar
  8. Cattaneo, F.: 1999, Astrophys. J. 515, L39.ADSCrossRefGoogle Scholar
  9. Collados, M.: 2001, In: M. Sigwarth (ed.): ASP Conf. Ser. 236: Advanced Solar Polarimetry — Theory, Observation, and Instrumentation. p. 255.Google Scholar
  10. Deinzer, W., G. Hensler, M. Schüssler, and E. Weisshaar: 1984, Astron. Astrophys. 139, 435.ADSGoogle Scholar
  11. Domínguez Cerdeña, I., F. Kneer, and J. Sánchez Almeida: 2003, Astrophys. J.. In press.Google Scholar
  12. Emonet, T. and F. Cattaneo: 2001, Astrophys. J. 560, L197.ADSCrossRefGoogle Scholar
  13. Frazier, E. N. and J. O. Stenflo: 1972, Solar Phys. 27, 330.ADSCrossRefGoogle Scholar
  14. Galloway, D. J., M. R. E. Proctor, and N. O. Weiss: 1977, Nature 266, 686.ADSCrossRefGoogle Scholar
  15. Grossmann-Doerth, U., M. Schuessler, and O. Steiner: 1998, Astron. Astrophys. 337, 928.ADSGoogle Scholar
  16. Hasan, S. S. and A. A. van Ballegooijen: 1998, In: R Donahue and J. Bookbinder (eds.): ASP Conf. Ser. 154: Cool Stars, Stellar Systems, and the Sun, Vol. 10. p. 630.Google Scholar
  17. Howard, R. and J. O. Stenflo: 1972, Solar Phys. 22, 402.ADSCrossRefGoogle Scholar
  18. Keppens, R. and V. Martinez Pillet: 1996, Astron. Astrophys. 316, 229.ADSGoogle Scholar
  19. Krause, F. and K.-H. Rädler: 1980, Mean-Field Magnetohydrodynamics and Dynamo Theory. Berlin: Akademie-Verlag.zbMATHGoogle Scholar
  20. Leka, K. D. and O. Steiner: 2001, Astrophys. J. 552, 354.ADSCrossRefGoogle Scholar
  21. Lin, H.: 1995, Astrophys. J. 446, 421.ADSCrossRefGoogle Scholar
  22. Lin, H. and T. Rimmele: 1999, Astrophys. J. 514, 448.ADSCrossRefGoogle Scholar
  23. Lites, B. W.: 2002, Astrophys. J. 573, 431.ADSCrossRefGoogle Scholar
  24. Lites, B. W., K. D. Leka, A. Skumanich, V. Martinez Pillet, and T. Shimizu: 1996, Astrophys. J. 460, 1019.ADSCrossRefGoogle Scholar
  25. Muller, R.: 1985, Solar Phys. 100, 237.ADSCrossRefGoogle Scholar
  26. Ossendrijver, M., M. Stix, A. Brandenburg, and G. Rüdiger: 2002, Astron. Astrophys. 394, 735.ADSzbMATHCrossRefGoogle Scholar
  27. Petrovay, K. and G. Szakaly: 1993, Astron. Astrophys. 274, 543.ADSGoogle Scholar
  28. Rajaguru, S. P. and S. S. Hasan: 2000, Astrophys. J. 544, 522.ADSCrossRefGoogle Scholar
  29. Roberts, B. and A. R. Webb: 1978, Solar Phys. 56, 5.ADSCrossRefGoogle Scholar
  30. Rutten, R. J., R. H. Hammerschlag, P. Sütterlin, and F. C. M. Bettonvil: 2001, In: M. Sigwarth (ed.): ASP Conf. Ser. 236: Advanced Solar Polarimetry — Theory, Observation, and Instrumentation. p. 25.Google Scholar
  31. Sánchez Almeida, J.: 2001, Astrophys. J. 556, 928.ADSCrossRefGoogle Scholar
  32. Sánchez Almeida, J. and B. W. Lites: 2000, Astrophys. J. 532, 1215.ADSCrossRefGoogle Scholar
  33. Socas-Navarro, H. and J. Sánchez Almeida: 2002, Astrophys. J. 565, 1323.ADSCrossRefGoogle Scholar
  34. Solanki, S. K., D. Zufferey, H. Lin, I. Rueedi, and J. R. Kuhn: 1996, Astron. Astrophys. 310, L33.ADSGoogle Scholar
  35. Spruit, H. C.: 1976, Solar Phys. 50, 269.ADSCrossRefGoogle Scholar
  36. Spruit, H. C.: 1979, Solar Phys. 61, 363.ADSCrossRefGoogle Scholar
  37. Spruit, H. C. and E. G. Zweibel: 1979, Solar Phys. 62, 15.ADSCrossRefGoogle Scholar
  38. Stein, R. and Å. Nordlund: 1998, Astrophys. J. 499, 914.ADSCrossRefGoogle Scholar
  39. Stein, R. F., D. Bercik, and Å. Nordlund: 2003, Il Nuovo Cimento. In press.Google Scholar
  40. Steiner, O.: 1996, In: D. Schmitt and H. Voigt (eds.): Solar and Galactic Magnetic Fields. Göttingen, Vandenhoeck & Ruprecht.Google Scholar
  41. Steiner, O.: 1999, In: B. Schmieder, A. Hofmann, and J. Staude (eds.): ASP Conf. Ser. 184: Third Advances in Solar Physics Euroconference: Magnetic Fields and Oscillations. p. 38.Google Scholar
  42. Steiner, O., U. Grossmann-Doerth, M. Knoelker, and M. Schuessler: 1998, Astrophys. J. 495, 468.ADSCrossRefGoogle Scholar
  43. Stenflo, J. and R. Holzreuter: 2003a, In: A. Pevtsov and H. Uitenbroek (eds.): Current Theoretical Models and Future High Resolution Solar Observations: Preparing for ATST. ASP, Conference Series. In press.Google Scholar
  44. Stenflo, J. and R. Holzreuter: 2003b, In: H. Sawaya-Lacoste (ed.): Magnetic Coupling of the Solar Atmosphere. ASP, Conference Series. In press.Google Scholar
  45. Stenflo, J. O.: 1989, Astron. Astrophys. Rev 1, 3.ADSCrossRefGoogle Scholar
  46. Stix, M.: 1989, The Sun. An Introduction. Springer, Berlin.Google Scholar
  47. Takeuchi, A.: 1999, Astrophys. J. 522, 518.ADSCrossRefGoogle Scholar
  48. Title, A. M. and T. E. Berger: 1996, Astrophys. J. 463, 797.ADSCrossRefGoogle Scholar
  49. Tobias, S. M., N. H. Brummell, T. L. Clune, and J. Toomre: 1998, Astrophys. J. 502, L177.ADSCrossRefGoogle Scholar
  50. van Ballegooijen, A.: 1984, In: S. Keil (ed.): Small-Scale Dynamical Processes in Quiet Stellar Atmospheres. p. 260, NSO/SP Workshop Ser. 5, Sunspot, NM.Google Scholar
  51. Vögler, A. and M. Schüssler: 2003, “. Astron. Nachrichten.In press.Google Scholar
  52. Vögler, A., S. Shelyag, M. Schüssler, F. Cattaneo, T. Emonet, and T. Linde: 2003, ‘’. In: N. Piskunov, W. W. Weiss, and D. F. Gray (eds.): Modelling of Stellar Atmospheres, IAU Symp. 210. San Francisco, Astronomical Society of the Pacific Conference Series. In press.Google Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2003

Authors and Affiliations

  • O. Steiner
    • 1
  1. 1.Kiepenheuer-Institut für SonnenphysikFreiburgGermany

Personalised recommendations