Kilohertz Gravitational Waves from Binary Neutron Star Mergers: Inference of Postmerger Signals with the Einstein Telescope

Understand

Next-generation detectors are expected to be sensitive to postmerger signals from binary neutron star coalescences and thus to directly probe the remnant dynamics.

• We investigate the scientific potential of postmerger detections with the Einstein Telescope using full Bayesian analyses with the state-of-the-art waveform model ${\tt NRPMw}$.
• We find that: (i) Postmerger signals with signal-to-noise ratio (SNR) ${\sim}7$ can be confidently detected with a Bayes' factor of $\log{\cal B}\simeq 5$ ($\rm e$-folded) and the posterior distributions report informative measurements already at SNR ${\sim}6$ for some noise realizations.
• (ii) The postmerger peak frequency $f_2$ can be confidently identified at SNR $7$ with errors of $O(1~{\rm kHz})$, that decrease below $O(100~{\rm Hz})$ for SNR 10.