Models of binary neutron star remnants with tabulated equations of state

Abstract

The emergence of novel differential rotation laws that can reproduce the rotational profile of binary neutron star merger remnants has opened the way for the construction of equilibrium models with properties that resemble those of remnants in numerical simulations. We construct models of merger remnants, using a recently introduced 4-parameter differential rotation law and three tabulated, zero-temperature equations of state. The models have angular momenta that are determined by empirical relations, constructed through numerical simulations. After a systematic exploration of the parameter space of merger remnant equilibrium sequences, which includes the determination of turning points along constant angular momentum sequences, we find that a particular rotation law can reproduce the threshold mass to prompt collapse to a black hole with a relative difference of only $\sim 1\%$ with respect to numerical simulations, in all cases considered. Furthermore, our results indicate a possible correlation between the compactness of equilibrium models of remnants at the threshold mass and the compactness of maximum-mass nonrotating models. Another key prediction of binary neutron star merger simulations is a relatively slowly rotating inner region, where the angular velocity $\Omega$ (as measured by an observer at infinity) is mostly due to the frame dragging angular velocity $\omega$. In our investigation of the parameter space of the adopted differential rotation law, we naturally find quasi-spherical (Type A) remnant models with this property. Our investigation clarifies the impact of the differential rotation law and of the equation of state on key properties of binary neutron star remnants and lays the groundwork for including thermal effects in future studies.

[v1] 18 pages, 28 figures, [v2] 20 pages, 31 figures, appendix added, extra discussion on frame dragging contribution, matches published version, [v3] corrected a misprint in Fig.18, article's results unaffected

References in corpus (39)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• Shapiro delay measurement of a two solar mass neutron star
• A Massive Pulsar in a Compact Relativistic Binary
• Multi-messenger Observations of a Binary Neutron Star Merger
• Gravitational Waves and Gamma-rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A
• An Ordinary Short Gamma-Ray Burst with Extraordinary Implications: Fermi-GBM Detection of GRB 170817A
• A NICER View of the Massive Pulsar PSR J0740+6620 Informed by Radio Timing and XMM-Newton Spectroscopy
• Neutron-star radius constraints from GW170817 and future detections
• Challenges and Opportunities of Gravitational Wave Searches at MHz to GHz Frequencies
• Binary Neutron Star Mergers: Dependence on the Nuclear Equation of State
• Search for post-merger gravitational waves from the remnant of the binary neutron star merger GW170817
• The Dynamics of Binary Neutron Star Mergers and of GW170817
• Properties of hypermassive neutron stars formed in mergers of spinning binaries
• Neutron-star Radius from a Population of Binary Neutron Star Mergers
• Numerical relativity simulations of neutron star merger remnants using conservative mesh refinement
• First 100 ms of a long-lived magnetized neutron star formed in a binary neutron star merger
• Inferring the post-merger gravitational wave emission from binary neutron star coalescences
• Exploring the sensitivity of gravitational wave detectors to neutron star physics
• The evolution of binary neutron star post-merger remnants: a review
• AT2017gfo: Bayesian inference and model selection of multi-component kilonovae and constraints on the neutron star equation of state
• Prospects For High Frequency Burst Searches Following Binary Neutron Star Coalescence With Advanced Gravitational Wave Detectors
• Realistic Finite-Temperature Effects in Neutron Star Merger Simulations
• On the stability and maximum mass of differentially rotating relativistic stars
• Binary Neutron Star Merger Simulations with a Calibrated Turbulence Model
• Modeling differential rotations of compact stars in equilibriums
• Gravitational wave detectors with broadband high frequency sensitivity
• Universal relations for differentially rotating relativistic stars at the threshold to collapse
• Multimessenger Binary Mergers Containing Neutron Stars: Gravitational Waves, Jets, and $\mathbf{\gamma }$-Ray Bursts
• Detection and parameter estimation of binary neutron star merger remnants
• The Radius of PSR J0740+6620 from NICER and XMM-Newton Data
• A new view on the maximum mass of differentially rotating neutron stars
• Axisymmetric models for neutron star merger remnants with realistic thermal and rotational profiles
• Tuning Advanced LIGO to kilohertz signals from neutron-star collisions
• Equilibrium sequences of differentially rotating stars with post-merger-like rotational profiles
• Revisiting the maximum mass of differentially rotating neutron stars in general relativity: Übermassive stars with realistic equations of state
• Instabilities in neutron-star postmerger remnants
• Numerical Inside View of Hypermassive Remnant Models for GW170817
• Maximum Mass Of Differentially Rotating Strange Quark Stars
• Multi-Messenger Astrophysics with THESEUS in the 2030s