Two-dimensional simulations of solar-like models with artificially enhanced luminosity. II. Impact on internal gravity waves

Abstract

Artificially increasing the luminosity and the thermal diffusivity of a model is a common tactic adopted in hydrodynamical simulations of stellar convection. In this work, we analyse the impact of these artificial modifications on the physical properties of stellar interiors and specifically on internal gravity waves. We perform two-dimensional simulations of solar-like stars with the MUSIC code. We compare three models with different luminosity enhancement factors to a reference model. The results confirm that properties of the waves are impacted by the artificial enhancement of the luminosity and thermal diffusivity. We find that an increase in the stellar luminosity yields a decrease in the bulk convective turnover timescale and an increase in the characteristic frequency of excitation of the internal waves. We also show that a higher energy input in a model, corresponding to a larger luminosity, results in higher energy in high frequency waves. Across our tests with the luminosity and thermal diffusivity enhanced together by up to a factor of 104, our results are consistent with theoretical predictions of radiative damping. Increasing the luminosity also has an impact on the amplitude of oscillatory motions across the convective boundary. One must use caution when interpreting studies of internal gravity waves based on hydrodynamical simulations with artificially enhanced luminosity.

16 pages, 13 figures; accepted for publication in A&A

References in corpus (14)

• Angular momentum transport by heat-driven g-modes in slowly pulsating B stars
• Angular Momentum Transport via Internal Gravity Waves in Evolving Stars
• Three-Dimensional Simulations of Massive Stars: I. Wave Generation and Propagation
• On the Chemical Mixing Induced by Internal Gravity Waves (IGW)
• Theoretical seismology in 3D : nonlinear simulations of internal gravity waves in solar-like stars
• Fully compressible simulations of waves and core convection in main-sequence stars
• Low-frequency variability in massive stars: Core generation or surface phenomenon?
• Solar overshoot region and small-scale dynamo with realistic energy flux
• Extreme value statistics for two-dimensional convective penetration in a pre-Main Sequence star
• Dynamics of Mixed Convective--Stably-Stratified Fluids
• Benchmarking the Multi-dimensional Stellar Implicit Code MUSIC
• Spherical-shell boundaries for two-dimensional compressible convection in a star
• Two-dimensional simulations of solar-like models with artificially enhanced luminosity -- I. Impact on convective penetration
• Coupled convection and internal gravity waves excited in water around its density maximum at 4°C

Cited by in corpus (12)

• The photometric variability of massive stars due to gravity waves excited by core convection
• 3D hydrodynamics simulations of internal gravity waves in red giant branch stars
• Multidimensional Simulations of Core Convection
• Stochastic excitation of internal gravity waves in rotating late F-type stars: A 3D simulation approach
• Two-dimensional simulations of internal gravity waves in a 5 $M_{\odot }$ Zero-Age-Main-Sequence model
• Amplitudes of Solar Gravity Modes: A Review
• In search of gravity mode signatures in main sequence solar-type stars observed by Kepler
• Mixing by Internal Gravity Waves in Stars: Assessing Numerical Simulations Against Theory
• Wave-Driven Mixing Enhanced by Rotation in Red Giant Branch Stars
• The shape of convection in 2D and 3D global simulations of stellar interiors
• Effects of stratification on overshooting and waves atop the convective core of $5M_{\odot }$ main-sequence stars
• Internally heated and fully compressible convection: flow morphology and scaling laws