3D non-LTE line formation in the solar photosphere and the solar oxygen abundance.
Abstract
We study the formation of OI and OH spectral lines in three-dimensional hydrodynamic models of the solar photosphere. The line source function of the OI 777nm triplet is allowed to depart from local thermodynamic equilibrium (lte), within the two-level-atom approximation. Comparison with results from 1D models show that the 3D models alleviate, but do not remove, the discrepancy between the oxygen abundances reported from non-lte work on the 777nm triplet and from the [OI] 630nm and OH lines. Results for the latter two could imply that the solar oxygen abundance is below 8.8. If this is confirmed, the discrepancy between theory and observation for the 777nm triplet lines might fall within the range of errors in equivalent-width measurements and f-values. The line source function of the 777nm triplet in the 1.5D approximation is shown to differ insignificantly from the full 3D non-lte result.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- October 1995
- DOI:
- 10.48550/arXiv.astro-ph/9505037
- arXiv:
- arXiv:astro-ph/9505037
- Bibcode:
- 1995A&A...302..578K
- Keywords:
-
- LINE: FORMATION;
- SUN: ABUNDANCES;
- SUN: GRANULATION;
- SUN: PHOTOSPHERE;
- Astrophysics
- E-Print:
- 10 pages, uuencoded compressed PostScript file including figures, to appear in Astronomy &