The solar photospheric abundance of carbon.Analysis of atomic carbon lines with the CO5BOLD solar model - Astrophysics > Solar and Stellar AstrophysicsReport as inadecuate




The solar photospheric abundance of carbon.Analysis of atomic carbon lines with the CO5BOLD solar model - Astrophysics > Solar and Stellar Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: The use of hydrodynamical simulations, the selection of atomic data, and thecomputation of deviations from local thermodynamical equilibrium for theanalysis of the solar spectra have implied a downward revision of the solarmetallicity. We are in the process of using the latest simulations computedwith the CO5BOLD code to reassess the solar chemical composition. We determinethe solar photospheric carbon abundance by using a radiation-hydrodynamicalCO5BOLD model, and compute the departures from local thermodynamicalequilibrium by using the Kiel code. We measure equivalent widths of atomic CIlines on high resolution, high signal-to-noise ratio solar atlases. Deviationsfrom local thermodynamic equilibrium are computed in 1D with the Kiel code. Ourrecommended value for the solar carbon abundance, relies on 98 independentmeasurements of observed lines and is AC=8.50+-0.06, the quoted error is thesum of statistical and systematic error. Combined with our recent results forthe solar oxygen and nitrogen abundances this implies a solar metallicity ofZ=0.0154 and Z-X=0.0211. Our analysis implies a solar carbon abundance which isabout 0.1 dex higher than what was found in previous analysis based ondifferent 3D hydrodynamical computations. The difference is partly driven byour equivalent width measurements we measure, on average, larger equivalentwidths with respect to the other work based on a 3D model, in part it islikely due to the different properties of the hydrodynamical simulations andthe spectrum synthesis code. The solar metallicity we obtain from the CO5BOLDanalyses is in slightly better agreement with the constraints ofhelioseismology than the previous 3D abundance results. Abridged



Author: E. Caffau 1, H.-G. Ludwig 2,1, P. Bonifacio 2,1,3, R. Faraggiana 4, M. Steffen 5, B. Freytag 6, I. Kamp 7, T.R. Ayres 8 1 GEPI, O

Source: https://arxiv.org/







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