Abstract
The excitation of -mode in a neutron star member of coalescing binaries accelerates the merger course, and thereby introduces a phase shift in the gravitational waveform. Emphasizing the tidal phase shift by aligned, rotating stars, we provide an accurate, yet economical, method to generate -mode-involved, premerger waveforms using realistic spin-modulated -mode frequencies for some viable equations of state. We find for slow-rotating stars that the dephasing effects of the dynamical tides can be uniquely, equation-of-state-independently determined by the direct observables (chirp mass , symmetric ratio , and the mutual tidal deformability ), while this universality is gradually lost for increasing spin. For binaries with fast rotating members () the phase shift due to the -mode will exceed the uncertainty in the waveform phase at reasonable signal-to-noise ratio () and cutoff frequency of . Assuming a high cutoff frequency of and fast () members, a significant phase shift of rads has been found. For systems involving a rapidly spinning star (potentially the secondary of GW190814), neglecting the -mode effect in the waveform templates can therefore lead to considerable systemic errors in the relevant analysis. In particular, the dephasing due to -mode is larger than that caused by equilibrium tides by a factor of , which may lead to a considerably overestimated tidal deformability if dynamical tidal contribution is not accounted. The possibility of accompanying precursors flares due to -mode excitation is also discussed.
2 More- Received 3 May 2022
- Accepted 6 September 2022
DOI:https://doi.org/10.1103/PhysRevD.106.064052
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