Stochastic excitation of gravity waves in rapidly rotating massive stars

TL;DR

This paper investigates how rapid rotation influences the stochastic excitation of gravity waves in massive stars, highlighting two excitation regimes and implications for stellar angular momentum transport.

Contribution

It introduces a new analysis of the Coriolis acceleration's effect on stochastic wave excitation, revealing two distinct regimes based on wave frequency.

Findings

Identification of super-inertial and sub-inertial excitation regimes

Demonstration of rotation's impact on wave excitation efficiency

Discussion of implications for angular momentum transport

Abstract

Stochastic gravity waves have been recently detected and characterised in stars thanks to space asteroseismology and they may play an important role in the evolution of stellar angular momentum. In this context, the observational study of the CoRoT hot Be star HD 51452 suggests a potentially strong impact of rotation on stochastic excitation of gravito-inertial waves in rapidly rotating stars. In this work, we present our results on the action of the Coriolis acceleration on stochastic wave excitation by turbulent convection. We study the change of efficiency of this mechanism as a function of the waves' Rossby number and we demonstrate that the excitation presents two different regimes for super-inertial and sub-inertial frequencies. Consequences for rapidly rotating early-type stars and the transport of angular momentum in their interiors are discussed.