Photometric detection of internal gravity waves in upper main-sequence stars: III. Comparison of amplitude spectrum fitting and Gaussian process regression using CELERITE2

Context. Recent studies of massive stars using high-precision space photometry have revealed that they commonly exhibit stochastic low-frequency (SLF) variability. This has been interpreted as being caused by internal gravity waves excited at the interface of convective and radiative regions within stellar interiors, such as the convective core or sub-surface convection zones, or being caused by dynamic turbulence associated with sub-surface convection zones within the envelopes of main-sequence massive stars.