The oscillations are standing pressure and mixed pressure-gravity modes that are excited over a range in frequency, with the amplitudes roughly following a bell-shaped distribution. Unlike opacity-driven oscillators, all the modes in the frequency range are excited, making the oscillations relatively easy to identify.
These oscillations encompass a range of standing pressure and mixed pressure-gravity waves, characterized by frequency-dependent amplitudes peaking in the middle. Unlike other wave phenomena, this type excites all modes within the frequency range, making them easily recognizable.