Astron. Astrophys. 324, 281-288 (1997)

1-D and 2-D model atmospheres: iron and lithium LTE abundances in the Sun

A.S. Gadun and Ya.V. Pavlenko

The Main Astronomical Observatory of Academy of Sciences of Ukraine, Goloseevo, 252650 Kiev-22, Ukraine

Received 25 January 1996 / Accepted 15 January 1997

Abstract

We discuss LTE abundance determinations of iron and lithium in the solar atmosphere using a grid of one-dimensional (1-D) and two-dimensional (2-D) model atmospheres. These models differ mainly in the convection treatment. We found that the influence of atmospheric inhomogeneities on the iron abundance comprises 0.1 dex for weak Fe I lines with low excitation potentials, and does not exceed 0.05 dex for weak Fe II lines. 2-D models show lower iron abundances for Fe I lines. On the other hand, lithium abundances obtained for 1-D homogeneous and 2-D inhomogeneous model atmospheres differ up to 0.1-0.2 dex. 2-D model atmospheres result in lower lithium abundances, in contradiction with the recent suggestion of Kurucz (1995).

Key words: Sun: abundances Sun: photosphere line: formation

Send offprint requests to: Ya.V. Pavlenko

Contents

• 1. Introduction
• 2. Model atmospheres
  • 2.1. 2-D models
  • 2.2. 1-D models
  • 2.3. Comparison of temperature structures of model atmospheres
• 3. Line lists
• 4. Line computations
  • 4.1. 1-D, OGA, and MSA models
  • 4.2. 2D models
• 5. Results
  • 5.1. Iron
    • 5.1.1. Fe I and Fe II lines: and values obtained with 2-D models
    • 5.1.2. Fe I lines: for set of 1-D models
    • 5.1.3. Fe II lines: for set of 1-D models
  • 5.2. Lithium
    • 5.2.1. 1-D models
    • 5.2.2. 2-D models
• 6. Discussion
• Acknowledgements
• References

© European Southern Observatory (ESO) 1997

Online publication: May 26, 1998

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