Wednesday 10 Nov 2021: Modelling waves in stellar interiors - Impact of simulations with artificially enhanced luminosity
Arthur Le Saux -
4th Floor, Physics + remote 14:00-15:00
The importance of waves propagating in the stars is twofold. First, they offer an incredible opportunity to unveil stellar internal structure and dynamics thanks to the observation of oscillations modes of stars, this is the field of asterseismology. Secondly, they have an impact on the internal structure and evolution of stars as they can transport angular momentum, energy and chemical elements between different region of the star. This presentation will particularly focus on internal gravity waves (IGW). Their detection and characterisation in stars, particularly in solar-like stars, is very difficult and remain a long standing challenge. This is why numerical simulations offer a great opportunity to study and constraint IGW properties. However, the wide range of time and length scales that characterise stellar interiors is a challenge for numerical simulations. In addition, the study of IGW requires simulating a large region of a star, including the convective and the radiative zones because these waves are produced by the nonlinear interactions between these two regions. To overcome numerical difficulties inherent to stellar hydrodynamics, such as numerical stability and thermal relaxation, an artificial increase of the stellar luminosity and of the thermal diffusivity by several orders of magnitudes is a commonly used tactic. In this talk, I will review some previous results concerning simulation and observation of IGW in stars. Then I will present 2D simulations of solar-like models with artificially enhanced luminosity and describe how this method impact IGW properties.