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Average Variations of Photospheric FeI and FeII Line Parameters as Function of the Magnetic Filling Factor

Published online by Cambridge University Press:  08 February 2017

P.N. Brandt  and
M. Steinegger
P.N. Brandt
Affiliation:
1Kiepenheuer-Institut für Sonnenphysik Schöneckstr. 6 D-7800 FREIBURG, F.R.G.
M. Steinegger
Affiliation:
2Insitut für Astronomie Universitåtsplatz 5 A-8010 GRAZ, Austria

Abstract

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A series of 17 Fourier transform spectra taken at the McMath telescope near disk center in regions of different magnetic field strengths were analyzed. Applying a multi-variate regression analysis magnetic filling factors 0 < α ≥ 0.11 were determined. With α increasing from 0 to 0.11, line bisectors averaged over groups of lines of similar depth are found to show a blue shift decreasing from 0.35 km s–1 to nearly 0.1 km s–1, when referred to the MgI line λ5172.7å. The bisectors of FeII lines exhibit smaller blue shifts than FeI lines. The increase of bisector red shift near the continuum with increasing α, found earlier by Brandt and Solanki (1987), was confirmed and is tentatively interpreted as a manifestation of downdrafts in the vicinity of flux tubes (Deinzer et al., 1984).

A significant increase of line width (typically between 3 and 8%, depending on line strength) and a decrease of line depth is found with increasing filling factor. For strong lines the equivalent width W shows no variation or a slight increase, while for the weaker lines a reduction of W between a few % and > 10% is found.

Type
I. Global Properties of the Photosphere
Information
Symposium - International Astronomical Union , Volume 138: Solar Photosphere: Structure, Convection and Magnetic Fields , 1990 , pp. 41 - 46
Copyright
Copyright © Kluwer 1990 

References

REFERENCES

Adam, M.G., Ibbetson, P.A., Petford, A.D.: 1976, Mon. Not. Roy. Astron. Soc. 177, 687 Google Scholar
Brandt, P.N., Schröter, E.-H.: 1982, Solar Phys. 79, 3 Google Scholar
Brandt, P.N., Schröter, E.-H.: 1984, Small-Scale Dynamical Processes in Quiet Stellar Atmospheres , ed. Keil, S., NSO Conf., 371 Google Scholar
Brandt, P.N., Solanki, S.K.: 1987, The Role of Fine-Scale Magnetic Fields on the Structure of the Solar Atmosphere , eds. Schröter, E.-H., Vazquez, M., Wyller, A.A., Cambridge Univ. Press, 82 Google Scholar
Brandt, P.N., Solanki, S.K.: 1989, in preparation Google Scholar
Cavallini, F., Ceppatelli, G., Righini, A.: 1985, Astron. Astrophys. 143, 116 Google Scholar
Cavallini, F., Ceppatelli, G., Righini, A.: 1988, Astron. Astrophys. 205, 278 Google Scholar
Deinzer, W., Hensler, G., Schüssler, M., Weisshaar, E.: 1984, Astron. Astrophys. 139, 435 Google Scholar
Dravins, D.: 1982, Ann. Rev. Astron. Astrophys. 20, 61 CrossRefGoogle Scholar
Dravins, D.: 1987a, Astron. Astrophys. 172, 200 Google Scholar
Dravins, D.: 1987b, Astron. Astrophys. 172, 211 Google Scholar
Dravins, D., Lindegren, L., Nordlund, Å.: 1981, Astron. Astrophys. 96, 345 Google Scholar
Gray, D.F.: 1982, Astrophys. J. 255, 200 Google Scholar
Hughes, D.W., Proctor, M.R.E.: 1988, Ann. Rev. Fluid Mech. 20, 187 Google Scholar
Immerschitt, S., Schröter, E.-H.: 1987, The Role of Fine-Scale Magnetic Fields on the Structure of the Solar Atmosphere , eds. Schröter, E.-H., Vazquez, M., Wyller, A.A., Cambridge Univ. Press, 53 Google Scholar
Immerschitt, S., Schröter, E.-H.: 1989, Astron. Astrophys. 208, 307 Google Scholar
Kaisig, M., Schröter, E.-H.: 1983, Astron. Astrophys. 117 305 Google Scholar
Kavetsky, A., O'Mara, B.J.: 1984, Solar Phys. 92, 47 Google Scholar
Keil, S.L., Yackovich, F.H.: 1981, Solar Phys. 69, 213 Google Scholar
Livingston, W.C.: 1982, Nature 297, 208 Google Scholar
Livingston, W.C.: 1983, Solar and Stellar Magnetic Fields: Origins and Coronal Effects , ed. Stenflo, J.O., IAU Symp. No. 102, 149 Google Scholar
Mattig, W., Nesis, A.: 1976, Solar Phys. 50, 255 Google Scholar
Mattig, W., Hanslmeier, A., Nesis, A.: 1989, Solar and Stellar Granulation , Proc. NATO Adv. Res. Workshop, Capri, June 21-25, eds. Rutten, R. and Severino, G., Kluwer, Dordrecht, 187 CrossRefGoogle Scholar
Miller, P., Foukal, P., Keil, S.: 1984, Solar Phys. 92, 33 Google Scholar
Nesis, A., Fleig, K.-H., Mattig, W.: 1989, Solar and Stellar Granulation , Proc. NATO Adv. Res. Workshop, Capri, June 21-25, eds. Rutten, R.J. and Severino, G., Kluwer, Dordrecht, 289 Google Scholar
Nordlund, Å.: 1986, Small Magnetic Flux Concentrations in the Solar Photosphere , eds. Deinzer, W., Knölker, M., Voigt, H.H., Vandenbeck & Ruprecht, Göttingen, 83 Google Scholar
Pierce, A.K., Breckinridge, J.B.: 1973, Kitt Peak National Obs. Contr. No. 559 Google Scholar
Schröter, E.-H.: 1957, Z. Astrophysik 41, 141 Google Scholar
Solanki, S.K.: 1986, Astron. Astrophys. 168, 311 Google Scholar
Solanki, S.K., Stenflo, J.O.: 1985, Astron. Astrophys. 148, 123 Google Scholar
Stenflo, J.O., Lindegren, L.: 1977, Astron. Astrophys. 59, 367 Google Scholar
Title, A.M., Tarbell, T.D., Simon, G.W., and the SOUP Team: 1986, Adv. Space Res. Vol. 6, No. 8, 253 Google Scholar
Title, A.M., Tarbell, T.D., Topka, K.P., Ferguson, S.H., Shine, R.A., and the SOUP Team: 1989, Astrophys. J. 336, 475 CrossRefGoogle Scholar