Solar abundances and granulation effects

TL;DR

This paper re-evaluates solar elemental abundances using advanced 3D hydrodynamical models and compares results with previous studies, addressing discrepancies caused by granulation effects and model choices.

Contribution

It provides an independent re-derivation of solar abundances employing state-of-the-art 3D simulations and analyzes the impact of granulation effects on abundance determinations.

Findings

Hydrodynamical models influence abundance measurements but do not cause the recent metallicity revision.

The study offers new abundance values based on line profile fitting and spectral analysis.

Comparison shows consistency with some previous results, but highlights model-dependent differences.

Abstract

The solar abundances have undergone a major downward revision in the last decade, reputedly as a result of employing 3D hydrodynamical simulations to model the inhomogeneous structure of the solar photosphere. The very low oxygen abundance advocated by Asplund et al. (2004), A(O)=8.66, together with the downward revision of the carbon and nitrogen abundances, has created serious problems for solar models to explain the helioseismic measurements. In an effort to contribute to the dispute we have re-derived photospheric abundances of several elements independently of previous analysis. We applied a state-of-the art 3D (CO5BOLD) hydrodynamical simulation of the solar granulation as well as different 1D model atmospheres for the line by line spectroscopic abundance determinations. The analysis is based on both standard disc-centre and disc-integrated spectral atlases; for oxygen we acquired in addition spectra at different heliocentric angles. The derived abundances are the result of equivalent width and/or line profile fitting of the available atomic lines. We discuss the different granulation effects on solar abundances and compare our results with previous investigations. According to our investigations hydrodynamical models are important in the solar abundance determination, but are not responsible for the recent downward revision in the literature of the solar metallicity.