Kilohertz gravitational waves from binary neutron star mergers: Numerical-relativity informed postmerger model
M. Breschi, Sebastiano Bernuzzi, K. Chakravarti, Alessandro Camilletti, Aviral Prakash, Albino Perego
Abstract
We present NRPMw, an analytical model of gravitational-waves from neutron star merger remnants informed using 618 numerical relativity (NR) simulations. NRPMw is designed in the frequency domain using a combination of complex Gaussian wavelets. The wavelet's parameters are calibrated to equations of state (EOSs) insensitive relations from NR data. The NR simulations are computed with 21 EOSs (seven of which are finite-temperature microphysical models, and three of which contain quark phase transitions or hyperonic degrees of freedom) and span total binary masses $M\ensuremath{\in}[2.4,3.4]{M}_{\ensuremath{\bigodot}}$, mass ratios up to $q=2$, and (nonprecessing) dimensionless spins magnitudes up to 0.2. The theoretical uncertainties of the EOS-insensitive relations are incorporated in NRPMw using recalibration parameters that enhance the flexibility and accuracy of the model. NRPMw is NR faithful with fitting factors $\ensuremath{\gtrsim}0.9$ computed on an independent validation set of 102 simulations.