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A Reappraisal of the Solar Photospheric C/O Ratio

Carlos Allende Prieto·David L. Lambert·Martin Asplund
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Abstract

Accurate determination of photospheric solar abundances requires detailed modeling of the solar granulation and accounting for departures from local thermodynamical equilibrium (LTE). We argue that the forbidden C I line at 8727 A is largely immune to departures from LTE, and can be realistically modeled using LTE radiative transfer in a time-dependent three-dimensional simulation of solar surface convection. We analyze the [C I] line in the solar flux spectrum to derive the abundance log epsilon(C)= 8.39 +/- 0.04 dex. Combining this result with our parallel analysis of the [O I] 6300 A line, we find C/O=0.50 +/- 0.07, in agreement with the ratios measured in the solar corona from gamma-ray spectroscopy and solar energetic particles.

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Carlos Allende Prieto, David L. Lambert, Martin Asplund. 2002-06-06. A Reappraisal of the Solar Photospheric C/O Ratio. https://doi.org/10.1086/342095

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