Surface manifestation of stochastically excited internal gravity waves

Recent photometric observations of massive stars show ubiquitous low-frequency "red-noise" variability, which has been interpreted as internal gravity waves (IGWs). Simulations IGWs generated by convection smooth surface wave spectra, qualitatively matching the observed red-noise. On other hand, theoretical calculations Shiode et al (2013) and Lecoanet (2019) predict should manifest at regularly-spaced peaks associated with standing g-modes. In this work, we compare these approaches to simplified 2D numerical simulations. The simulations g-mode their surface, are in good agreement (2019). amplitude estimates did not take into account finite width peaks; after correcting for width, find However, need be run hundreds turnover times become visible; is a long time simulation, but short life star. final spectrum can predicted calculating energy flux much shorter simulations, then either applying theory or