2-D and 3-D Models of Convective Turbulence and Oscillations in Intermediate-Mass Main-Sequence Stars

TL;DR

This paper develops multidimensional models of convection and oscillations in intermediate-mass main-sequence stars, exploring their interactions, excitation mechanisms, and effects of rotation, providing new insights into stellar pulsations.

Contribution

It introduces three distinct multidimensional modeling approaches to study convection and oscillations in stars, advancing understanding of pulsation excitation and stellar interior dynamics.

Findings

Convection-oscillation interactions influence stellar pulsations.

Core convection can excite low-frequency gravity modes.

Rotation and overshooting affect pulsation spectra.

Abstract

We present multidimensional modeling of convection and oscillations in main-sequence stars somewhat more massive than the Sun, using three separate approaches: 1) Using the 3-D planar StellarBox radiation hydrodynamics code to model the envelope convection zone and part of the radiative zone. Our goals are to examine the interaction of stellar pulsations with turbulent convection in the envelope, excitation of acoustic modes, and the role of convective overshooting; 2) Applying the spherical 3-D MHD ASH (Anelastic Spherical Harmonics) code to simulate the core convection and radiative zone. Our goal is to determine whether core convection can excite low-frequency gravity modes, and thereby explain the presence of low frequencies for some hybrid gamma Doradus/delta Scuti variables for which the envelope convection zone is too shallow for the convective blocking mechanism to drive gravity modes; 3) Applying the ROTORC 2-D stellar evolution and dynamics code to calculate evolution with a variety of initial rotation rates and extents of core convective overshooting. The nonradial adiabatic pulsation frequencies of these nonspherical models are calculated using the 2-D pulsation code NRO. We present new insights into pulsations for stars of one to two solar masses gained by multidimensional modeling.