Spectral properties of the postmerger gravitationalwave signal from binary neutron stars
Abstract
Extending previous work by a number of authors, we have recently presented a new approach in which the detection of gravitational waves from merging neutron star binaries can be used to determine the equation of state of matter at nuclear density and hence the structure of neutron stars. In particular, after performing a large number of numericalrelativity simulations of binaries with nuclear equations of state, we have found that the postmerger emission is characterized by two distinct and robust spectral features. While the highfrequency peak was already shown to be associated with the oscillations of the hypermassive neutron star produced by the merger and to depend on the equation of state, we have highlighted that the lowfrequency peak is related to the merger process and to the total compactness of the stars in the binary. This relation is essentially universal and provides a powerful tool to set tight constraints on the equation of state. We here provide additional information on the extensive analysis performed, illustrating the methods used, the tests considered, as well as the robustness of the results. We also discuss additional relations that can be deduced when exploring the data and how these correlate with various properties of the binary. Finally, we present a simple mechanical toy model that explains the main spectral features of the postmerger signal and can even reproduce analytically the complex waveforms emitted right after the merger.
 Publication:

Physical Review D
 Pub Date:
 March 2015
 DOI:
 10.1103/PhysRevD.91.064001
 arXiv:
 arXiv:1412.3240
 Bibcode:
 2015PhRvD..91f4001T
 Keywords:

 04.25.D;
 04.25.dk;
 04.30.Db;
 26.60.Kp;
 Numerical relativity;
 Numerical studies of other relativistic binaries;
 Wave generation and sources;
 Equations of state of neutronstar matter;
 General Relativity and Quantum Cosmology;
 Astrophysics  High Energy Astrophysical Phenomena;
 Astrophysics  Solar and Stellar Astrophysics
 EPrint:
 25 pages, 19 figures, 4 tables