On the surface physics affecting solar oscillation frequencies

TL;DR

This paper demonstrates that incorporating detailed physics of turbulent convection, including 3D hydrodynamical simulations and turbulent pressure, significantly improves the match between modeled and observed solar oscillation frequencies, reducing discrepancies to less than 3 μHz.

Contribution

The study introduces a comprehensive modeling approach that includes 3D hydrodynamical simulations and turbulent pressure to accurately reproduce solar oscillation frequencies.

Findings

Standard models overestimate frequencies by ~20 μHz.

Including 3D hydrodynamical effects reduces discrepancies to <3 μHz.

Physical modeling of turbulence explains surface effects in solar oscillations.

Abstract

Adiabatic oscillation frequencies of stellar models, computed with the standard mixing-length formulation for convection, increasingly deviate with radial order from observations in solar-like stars. Standard solar models overestimate adiabatic frequencies by as much as ~ 20 {\mu}Hz. In this letter, we address the physical processes of turbulent convection that are predominantly responsible for the frequency differences between standard models and observations, also called `surface effects'. We compare measured solar frequencies from the MDI instrument on the SOHO spacecraft with frequency calculations that include three-dimensional (3D) hydrodynamical simulation results in the equilibrium model, nonadiabatic effects, and a consistent treatment of the turbulent pressure in both the equilibrium and stability computations. With the consistent inclusion of the above physics in our model computation we are able to reproduce the observed solar frequencies to < 3 {\mu}Hz without the need of any additional ad-hoc functional corrections.