Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Gravitational waves from binary neutron star mergers with a spectral equation of state

Journal Article · · Physical Review. D.
 [1];  [2];  [3];  [4];  [4];  [5];  [6]
  1. University of New Hampshire, Durham, NH (United States); University of New Hampshire
  2. University of New Hampshire, Durham, NH (United States)
  3. Washington State University, Pullman, WA (United States)
  4. Cornell University, Ithaca, NY (United States)
  5. Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Potsdam (Germany)
  6. California Institute of Technology (CalTech), Pasadena, CA (United States)

In numerical simulations of binary neutron star systems, the equation of state of the dense neutron star matter is an important factor in determining both the physical realism and the numerical accuracy of the simulations. Some equations of state used in simulations are C2 or smoother in the pressure/density relationship function, such as a polytropic equation of state, but may not have the flexibility to model stars or remnants of different masses while keeping their radii within known astrophysical constraints. Other equations of state, such as tabular or piece-wise polytropic, may be flexible enough to model additional physics and multiple stars' masses and radii within known constraints, but are not as smooth, resulting in additional numerical error. We will study in this paper a recently developed family of equation of state, using a spectral expansion with sufficient free parameters to allow for a larger flexibility than current polytropic equations of state, and with sufficient smoothness to reduce numerical errors compared to tabulated or piece-wise polytropic equations of state. We perform simulations at three mass ratios with a common chirp mass, using two distinct spectral equations of state, and at multiple numerical resolutions. We evaluate the gravitational waves produced from these simulations, comparing the phase error between resolutions and equations of state, as well as with respect to analytical models. From our simulations we estimate that the phase difference at merger for binaries with a dimensionless weighted tidal deformability difference greater than Δ$$\tilde{Λ}$$=55 can be captured by the SpEC code for these equations of state.

Research Organization:
University of New Hampshire, Durham, NH (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Nuclear Physics (NP); National Science Foundation (NSF); National Aeronautics and Space Administration (NASA); ACCESS
Grant/Contract Number:
SC0020435; AC02-05CH11231
OSTI ID:
2406192
Alternate ID(s):
OSTI ID: 2473959
Journal Information:
Physical Review. D., Journal Name: Physical Review. D. Journal Issue: 2 Vol. 110; ISSN 2470-0010
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English

References (36)

A multidomain spectral method for solving elliptic equations journal May 2003
THC: a new high-order finite-difference high-resolution shock-capturing code for special-relativistic hydrodynamics journal October 2012
Primitive Variable Solvers for Conservative General Relativistic Magnetohydrodynamics journal April 2006
A new generalized harmonic evolution system journal July 2006
Reducing orbital eccentricity in binary black hole simulations journal May 2007
High-order fully general-relativistic hydrodynamics: new approaches and tests journal March 2014
Waveform uncertainty quantification and interpretation for gravitational-wave astronomy journal May 2023
Finite-temperature effects in dynamical spacetime binary neutron star merger simulations: validation of the parametric approach journal September 2022
Future prospects for constraining nuclear matter parameters with gravitational waves journal July 2019
Smooth equations of state for high-accuracy simulations of neutron star binaries journal November 2019
Parametrized equation of state for neutron star matter with continuous sound speed journal October 2020
High-accuracy waveforms for black hole-neutron star systems with spinning black holes journal March 2021
Improving the convergence order of binary neutron star merger simulations in the Baumgarte- Shapiro-Shibata-Nakamura formulation journal July 2022
Entropy-limited higher-order central scheme for neutron star merger simulations journal July 2022
Simulating neutron stars with a flexible enthalpy-based equation of state parametrization in spectre journal June 2023
High-accuracy comparison of numerical relativity simulations with post-Newtonian expansions journal December 2007
Initial data for black hole–neutron star binaries: A flexible, high-accuracy spectral method journal June 2008
Evolving black hole-neutron star binaries in general relativity using pseudospectral and finite difference methods journal November 2008
Extrapolating gravitational-wave data from numerical simulations journal December 2009
Spectral representations of neutron-star equations of state journal November 2010
Black-hole–neutron-star mergers at realistic mass ratios: Equation of state and spin orientation effects journal April 2013
First direct comparison of nondisrupting neutron star-black hole and binary black hole merger simulations journal September 2013
Simulations of inspiraling and merging double neutron stars using the Spectral Einstein Code journal June 2016
Constraining nuclear matter parameters with GW170817 journal February 2019
Gravitational waveforms from spectral Einstein code simulations: Neutron star-neutron star and low-mass black hole-neutron star binaries journal February 2019
GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral journal October 2017
GW170817: Measurements of Neutron Star Radii and Equation of State journal October 2018
GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo during the Second Part of the Third Observing Run journal December 2023
Key elements of robustness in binary black hole evolutions using spectral methods journal June 2014
Finite-temperature Extension for Cold Neutron Star Equations of State journal April 2019
Search for Post-merger Gravitational Waves from the Remnant of the Binary Neutron Star Merger GW170817 journal December 2017
GW190425: Observation of a Compact Binary Coalescence with Total Mass ∼ 3.4 M journal March 2020
Constraining the Dense Matter Equation of State with Joint Analysis of NICER and LIGO/Virgo Measurements journal April 2020
GW190814: Gravitational Waves from the Coalescence of a 23 Solar Mass Black Hole with a 2.6 Solar Mass Compact Object journal June 2020
Observation of Gravitational Waves from Two Neutron Star–Black Hole Coalescences journal June 2021
Constraints on the Dense Matter Equation of State and Neutron Star Properties from NICER’s Mass–Radius Estimate of PSR J0740+6620 and Multimessenger Observations journal September 2021

Similar Records

Dynamical ejecta from binary neutron star mergers: Impact of a small residual eccentricity and of the equation of state implementation
Journal Article · Tue Jul 02 00:00:00 EDT 2024 · Physical Review. D. · OSTI ID:2406191

A Comparison of Grid-based and SPH Binary Mass-transfer and Merger Simulations
Journal Article · Sat Apr 01 00:00:00 EDT 2017 · Astrophysical Journal, Supplement Series · OSTI ID:22661215

A Comparison of Grid-based and SPH Binary Mass-transfer and Merger Simulations
Journal Article · Wed Mar 29 00:00:00 EDT 2017 · The Astrophysical Journal. Supplement Series (Online) · OSTI ID:1454988