A new approach to the solar oxygen abundance problem

TL;DR

This paper introduces a robust, nearly model-independent spectro-polarimetric method to determine the solar oxygen abundance, providing a precise value with minimal model dependence.

Contribution

It presents a novel spectro-polarimetric approach analyzing Stokes V profile asymmetries to constrain solar oxygen abundance with high reliability.

Findings

Estimated oxygen abundance: logEO = 8.86 ± 0.07

Method shows very low model dependence

Results are robust against uncertainties in oscillator strengths

Abstract

In this work we present new data that sets strong constraints on the solar oxygen abundance. Our approach, based on the analysis of spectro-polarimetric observations, is almost model-independent and therefore extremely robust. The asymmetry of the Stokes V profile of the 6300 A [OI] and NiI blend is used as an indicator of the relative abundances of these two elements. The peculiar shape of the profile requires a value of EO = 730+/-100 ppm (parts per million), or logEO = 8.86+/-0.07 in the logarithmic scale commonly used in Astrophysics. The uncertainty range includes the model dependence as well as uncertainties in the oscillator strengths of the lines. We emphasize that the very low degree of model dependence in our analysis makes it very reliable compared to traditional determinations.