A Reappraisal of the Solar Photospheric C/O Ratio

This is the authors' abstract. We don't add key points for this paper.

An 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 dex. Combining this result with our log e(C) p 8.39 0.04 parallel analysis of [O i] l6300, we find , in agreement with the ratios measured in the solar C/O p 0.50 0.07 corona from gamma-ray spectroscopy and solar energetic particles.