Equation-of-state dependence of the gravitational-wave signal from the ring-down phase of neutron-star mergers

By A. Bauswein, Hans-Thomas Janka, K. Hebeler, A. S. M. Astrophysics, Garching, O. University, Columbus, E. Emmi, Darmstadt, T. U. Darmstadt. 2012

141 citations recorded by the source corpus.

Neutron-star (NS) merger simulations are conducted for 38 representative microphysical descriptions of high-density matter in order to explore the equation-of-state dependence of the postmerger ring-down phase. The formation of a deformed, oscillating, differentially rotating very massive NS is the typical outcome of the coalescence of two stars with 1.35 M⊙ for most candidate EoSs. The oscillations of this object imprint a pronounced peak in the gravitational-wave (GW) spectra, which is used to characterize the emission for a given model. The peak frequency of this postmerger GW signal correlates very well with the radii of nonrotating NSs, and thus allows to constrain the highdensity EoS by a GW detection. In the case of 1.35-1.35 M⊙ mergers the peak frequency scales particularly well with the radius of a NS with 1.6 M⊙, where the maximum deviation from this correlation is only 60 meters for fully microphysical EoSs which are compatible with NS observations. Combined with the uncertainty in the determination of the peak frequency it appears likely that a GW detection can measure the radius of a 1.6 M⊙ NS with an accuracy of about 100 to 200 meters. We also uncover relations of the peak frequency with the radii of nonrotating NSs with 1.35 M⊙ or 1.8 M⊙, with the radius or the central energy density of the maximum-mass TolmanOppenheimer-Volkoff configuration, and with the pressure or sound speed at a fiducial rest-mass density of about twice nuclear saturation density. Furthermore, it is found that a determination of the dominant postmerger GW frequency can provide an upper limit for the maximum mass of nonrotating NSs. The effect of variations of the binary setup are investigated and corresponding functional dependences between the peak frequency and radii of nonrotating NSs are derived. With higher total binary masses, correlations are tighter for radii of nonrotating NSs with higher masses. The prospects for a detection of the postmerger GW signal and a determination of the dominant GW frequency are estimated to be in the range of 0.015 to 1.2 events per year with the upcoming Advanced LIGO detector.

Subfields: Astronomy and Astrophysics, Geophysics

View Paper: https://www.semanticscholar.org/paper/e7b36828c2e807aaa497e17e41ec623f16422222

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Citations in the corpus

Neutron-star Radius Constraints from GW170817 and Future Detections (2017, background): “…(e.g. Faber et al. 2002; Flanagan & Hinderer 2008; Read et al. 2013; Del Pozzo et al. 2013; Abbott et al. 2017) or through the characteristic oscillations of the postmerger remnant (Bauswein & Janka 2012; Bauswein et al. 2012, 2014; Takami et al. 2014; Clark et al. 2014; Chatziioannou et al. 2017).”
Delayed outflows from black hole accretion tori following neutron star binary coalescence (2013, background): “…properties of the merging binary (e.g., Ajith et al. 2007; van der Sluys et al. 2008); a potential probe of the equation of state of dense matter (e.g., Faber et al. 2002; Shibata 2005; Read et al. 2009; Bauswein et al. 2012); and even a test of General Relativity itself (e.g. Cornish et al. 2011).”
Comprehensive nucleosynthesis analysis for ejecta of compact binary mergers (2014, methodology): “…has been shown to yield quantitatively accurate results for the oscillation modes of NS-merger remnants and for the properties of ejecta when compared to calculations solving the full Einstein equations (Bauswein et al. 2012, 2013b; Hotokezaka et al. 2013a; Takami, Rezzolla & Baiotti 2014).”
Red or blue? A potential kilonova imprint of the delay until black hole formation following a neutron star merger (2014, background): “For particularly nearby mergers, oscillations excited in the HMNS may be detectable in the GW strain data (Shibata 2005; Bauswein et al. 2012; Hotokezaka et al. 2013b).”
The Nuclear Symmetry Energy (2016, background): “In their pioneering works, Bauswein and Janka [152, 153] showed that it is possible to extract information about the EOS of nuclear matter from the analysis of the spectral properties of the post-merger signal.”
SYSTEMATICS OF DYNAMICAL MASS EJECTION, NUCLEOSYNTHESIS, AND RADIOACTIVELY POWERED ELECTROMAGNETIC SIGNALS FROM NEUTRON-STAR MERGERS (2013, methodology): “This is in conflict with values of 1.8 or 2 which have been widely used and work well for gravitational-wave determinations (Bauswein et al. 2012, 2010a).”
Signatures of magnetar central engines in short GRB light curves (2013, background): “On a more optimistic note, Bauswein et al. (2012) estimate that AdLIGO will be able to detect a post-merger signal associated with a newly formed massive NS with a rate of 0.015 – 1.2 yr−1.”
Constraining the Maximum Mass of Neutron Stars from Multi-messenger Observations of GW170817 (2017, background): “…2014; Read et al. 2013; Del Pozzo et al. 2013; Agathos et al. 2015; Lackey & Wade 2015; Chatziioannou et al. 2015) and for quasi-periodic oscillations of the post-merger remnant (e.g. Bauswein & Janka 2012; Bauswein et al. 2012; Clark et al. 2014; Bauswein & Stergioulas 2015; Bauswein et al. 2016).”