Sound speed and oscillation frequencies for solar models evolved with Los Alamos ATOMIC opacities

TL;DR

This study evaluates the impact of newly calculated Los Alamos ATOMIC opacities on solar models, showing improvements in sound speed profiles and oscillation frequencies, thereby addressing the solar abundance problem.

Contribution

It introduces updated ATOMIC opacities into solar models and compares their effects with existing OPAL data, highlighting improvements in helioseismic agreement.

Findings

ATOMIC opacities have steeper derivatives than OPAL in the solar interior.

Models with ATOMIC opacities better match observed sound speed profiles.

Partial mitigation of the solar abundance problem is achieved.

Abstract

Los Alamos National Laboratory has calculated a new generation of radiative opacities (OPLIB data using the ATOMIC code) for elements with atomic number Z=1-30 with improved physics input, updated atomic data, and finer temperature grid to replace the Los Alamos LEDCOP opacities released in the year 2000. We calculate the evolution of standard solar models including these new opacities, and compare with models evolved using the Lawrence Livermore National Laboratory OPAL (Iglesias and Rogers 1996) opacities. We use the solar abundance mixture of Asplund et al. (2009). The new Los Alamos ATOMIC opacities have steeper opacity derivatives than those of OPAL for temperatures and densities of the solar interior radiative zone. We compare the calculated nonadiabatic solar oscillation frequencies and solar interior sound speed to observed frequencies and helioseismic inferences. The calculated sound-speed profiles are similar for models evolved using either the updated Iben evolution code (see \cite{Guzik2010}), or the MESA evolution code (Paxton et al., 2015). The LANL ATOMIC opacities partially mitigate the "solar abundance problem".