Convective Excitation and Damping of Solar-like Oscillations

TL;DR

This paper combines 3D stellar atmosphere simulations with 1D models to understand the excitation and damping of solar-like oscillations, enabling more accurate predictions of stellar properties from asteroseismic data.

Contribution

It introduces a parameter-free, ab initio approach to predict oscillation frequencies and amplitudes, improving the theoretical understanding of mode excitation and damping in stars.

Findings

Good agreement between models and observations for target stars.

First estimation of $ u_{max}$ based on ab initio modeling.

Potential to predict stellar properties across the HR-diagram.

Abstract

The last decade has seen a rapid development in asteroseismology thanks to the CoRoT and Kepler missions. With more detailed asteroseismic observations available, it is becoming possible to infer exactly how oscillations are driven and dissipated in solar-type stars. We have carried out three-dimensional (3D) stellar atmosphere simulations together with one-dimensional (1D) stellar structural models of key benchmark turn-off and subgiant stars to study this problem from a theoretical perspective. Mode excitation and damping rates are extracted from 3D and 1D stellar models based on analytical expressions. Mode velocity amplitudes are determined by the balance between stochastic excitation and linear damping, which then allows the estimation of the frequency of maximum oscillation power, $\nu_{\max}$, for the first time based on ab initio and parameter-free modelling. We have made detailed comparisons between our numerical results and observational data and achieved very encouraging agreement for all of our target stars. This opens the exciting prospect of using such realistic 3D hydrodynamical stellar models to predict solar-like oscillations across the HR-diagram, thereby enabling accurate estimates of stellar properties such as mass, radius and age.