Internal Gravity Waves in Massive Stars: Angular Momentum Transport

TL;DR

This paper uses numerical simulations to demonstrate that internal gravity waves in massive stars efficiently transport angular momentum, influencing stellar evolution and explaining several observational phenomena.

Contribution

It provides the first detailed simulation-based analysis of IGW-driven angular momentum transport in massive stars, linking wave dynamics to observable stellar features.

Findings

IGW are generated efficiently in massive stars.

IGW transport angular momentum rapidly over large distances.

IGW influence stellar phenomena such as star-planet misalignments and binary orbits.

Abstract

We present numerical simulations of internal gravity waves (IGW) in a star with a convective core and extended radiative envelope. We report on amplitudes, spectra, dissipation and consequent angular momentum transport by such waves. We find that these waves are generated efficiently and transport angular momentum on short timescales over large distances. We show that, as in the Earth's atmosphere, IGW drive equatorial flows which change magnitude and direction on short timescales. These results have profound consequences for the observational inferences of massive stars, as well as their long term angular momentum evolution. We suggest IGW angular momentum transport may explain many observational mysteries, such as: the misalignment of hot Jupiters around hot stars, the Be class of stars, Ni enrichment anomalies in massive stars and the non-synchronous orbits of interacting binaries.