Seismic Solar Models from Ledoux discriminant inversions

TL;DR

This paper develops seismic solar models using Ledoux discriminant inversions to better match helioseismic data, addressing discrepancies caused by recent photospheric abundance updates and improving understanding of the Sun's internal structure.

Contribution

It introduces a novel seismic modeling approach that refines the Sun's internal structure by directly inverting the Ledoux discriminant, surpassing standard evolutionary models in accuracy.

Findings

Seismic models agree with helioseismic data within 0.1% for sound speed, density, and entropy proxy.

The method accurately determines the Ledoux discriminant profile of the Sun.

Seismic models outperform all standard and non-standard evolutionary models.

Abstract

The Sun constitutes an excellent laboratory of fundamental physics. With the advent of helioseismology, we were able to probe its internal layers with unprecedented precision. However, the current state of solar modelling is still stained by tedious issues. One of these problems is related to the disagreement between models computed with recent photospheric abundances and helioseismic constraints. We use solar evolutionary models as initial conditions for reintegrations of their structure using Ledoux discriminant inversions. The resulting models are defined as seismic solar models, satisfying the equations of hydrostatic equilibrium. They will allow us to better constrain the internal structure of the Sun and provide complementary information to that of evolutionary models. These seismic models were computed using various reference models with different equations of state, abundances and opacity tables. We check the robustness of our approach by confirming the good agreement of our seismic models in terms of sound speed, density and entropy proxy inversions as well as frequency-separation ratios of low-degree pressure modes. Our method allows us to determine with an excellent accuracy the Ledoux discriminant profile of the Sun and compute full profiles of this quantity. Our models show an agreement with seismic data of ~0.1% in sound speed, density and entropy proxy as well as with the observed frequency-separation ratios. They surpass all standard and non-standard evolutionary models including ad-hoc changes aiming at reproducing helioseismic constraints. The obtained seismic Ledoux discriminant profile as well as the consistent structure obtained from our procedure paves the way for renewed attempts at constraining the solar modelling problem and the missing physical processes acting in the solar interior by breaking free from the hypotheses of evolutionary models.