Evolution of the bursting-layer wave during a type I X-ray burst

In a popular scenario due to Heyl, quasi-periodic oscillations (QPOs) which are seen during type I X-ray bursts are produced by giant travelling waves in the neutron star bursting layer. Piro and Bildsten have proposed that during the burst cooling the wave in the bursting layer may convert into a deep crustal interface wave, which would cut off the visible QPOs. This cut-off would help explain the magnitude of the QPO frequency drift, which is otherwise overpredicted by a factor of several in Heyl's scenario. In this paper, we study the coupling between the bursting layer and the deep ocean. The coupling turns out to be weak and only a small fraction of the surface-wave energy gets transferred to that of the crustal-interface wave during the burst. Thus the crustal-interface wave is not likely to play a dynamical role during the burst, and no early QPO cut-off should occur.