Quasi-equilibrium models for triaxially deformed rotating compact stars

Abstract

Quasi-equilibrium models of rapidly rotating triaxially deformed stars are computed in general relativistic gravity, assuming a conformally flat spatial geometry (Isenberg-Wilson-Mathews formulation) and a polytropic equation of state. Highly deformed solutions are calculated on the initial slice covered by spherical coordinate grids, centered at the source, in all angular directions up to a large truncation radius. Constant rest mass sequences are calculated from nearly axisymmetric to maximally deformed triaxial configurations. Selected parameters are to model (proto-) neutron stars; the compactness is M/R = 0.001, 0.1, 0.14, 0.2 for polytropic index n = 0.3 and M/R = 0.001, 0.1, 0.12, 0.14 for n = 0.5. We confirmed that the triaxial solutions exist for these parameters as in the case of Newtonian polytropes. However, it is also found that the triaxial sequences become shorter for higher compactness, and those may disappear at a certain large compactness for the n = 0.5 case. In the scenario of the contraction of proto-neutron stars being subject to strong viscosity and rapid cooling, it is plausible that, once the viscosity driven secular instability sets in during the contraction, the proto-neutron stars are always maximally deformed triaxial configurations, as long as the compactness and the equation of state parameters allow such triaxial sequences. Detection of gravitational waves from such sources may be used as another probe for the nuclear equation of state.

13 pages, 5 figures

References in corpus (47)

• A unified equation of state of dense matter and neutron star structure
• Evolution of Protoneutron Stars
• Rotating Stars in Relativity
• Gravitational Radiation and Rotation of Accreting Neutron Stars
• Merger of binary neutron stars with realistic equations of state in full general relativity
• The Physics of Core-Collapse Supernovae
• Simulation of merging binary neutron stars in full general relativity: $\Gamma =2$ case
• Numerical Relativity and Compact Binaries
• Detecting gravitational wave emission from the known accreting neutron stars
• Gravitational Radiation from Rapidly Rotating Nascent Neutron Stars
• General relativistic simulations of magnetized binary neutron star mergers
• Merger of binary neutron stars of unequal mass in full general relativity
• Analytical representations of unified equations of state of neutron-star matter
• Numerical approach for high precision 3-D relativistic star models
• Gravitational Waves from the Merger of Binary Neutron Stars in a Fully General Relativistic Simulation
• Evolution of Proto-Neutron Stars with Quarks
• Dynamical instability of differentially rotating stars
• Construction of Highly Accurate Models of Rotating Neutron Stars - Comparison of Three Different Numerical Schemes
• Nonaxisymmetric Neutral Modes in Rotating Relativistic Stars
• Evolution of Proto-Neutron stars with kaon condensates
• Three-dimensional simulations of stellar core collapse in full general relativity: Nonaxisymmetric dynamical instabilities
• Dynamical bar-mode instability of differentially rotating stars: Effects of equations of state and velocity profiles
• Nonexistence of conformally flat slices of the Kerr spacetime
• Coalescing Binary Neutron Stars
• Thermodynamics of binary black holes and neutron stars
• A new numerical method for constructing quasi-equilibrium sequences of irrotational binary neutron stars in general relativity
• Deriving formulations for numerical computation of binary neutron stars in quasicircular orbits
• Testing a Simplified Version of Einstein's Equations for Numerical Relativity
• Gravitational Waves from Long-Duration Simulations of the Dynamical Bar Instability
• Properties of general relativistic, irrotational binary neutron stars in close quasiequilibrium orbits : Polytropic equations of state
• Dynamical Bar Instability in Rotating Stars: Effect of General Relativity
• A multi-domain spectral method for scalar and vectorial Poisson equations with non-compact sources
• Spontaneous Symmetry Breaking of Rapidly Rotating Stars in General Relativity
• Binary neutron stars: Equilibrium models beyond spatial conformal flatness
• Frequencies of f-modes in differentially rotating relativistic stars and secular stability limits
• Neutral Points of Oscillation Modes along Equilibrium Sequences of Rapidly Rotating Polytropes in General Relativity --- Application of The Cowling Approximation ---
• Are rotating strange quark stars good sources of gravitational waves?
• Gravitational Radiation from Rotational Instabilities in Compact Stellar Cores with Stiff Equations of State
• Gravitational Waves from the Dynamical Bar Instability in a Rapidly Rotating Star
• Numerical evolution of secular bar-mode instability induced by the gravitational radiation reaction in rapidly rotating neutron stars
• Relativistic dust disks and the Wilson-Mathews approach
• Jacobi-like bar mode instability of relativistic rotating bodies
• Numerical method for binary black hole/neutron star initial data: Code test
• A new numerical scheme to compute 3D configurations of quasiequilibrium compact stars in general relativity -- Application to synchronously rotating binary star systems --
• Viscosity driven instability in rotating relativistic stars
• The Secular Bar-Mode Instability in Rapidly Rotating Stars Revisited
• Post-Newtonian treatment of bar mode instability in rigidly rotating equilibrium configurations for polytropic stars

Cited by in corpus (18)

• Rotating Stars in Relativity
• Modeling differential rotations of compact stars in equilibriums
• Non-conformally flat initial data for binary compact objects
• A new code for equilibriums and quasiequilibrium initial data of compact objects
• Initial data for binary neutron stars with adjustable eccentricity
• Equilibrium solutions of relativistic rotating stars with mixed poloidal and toroidal magnetic fields
• New code for equilibriums and quasiequilibrium initial data of compact objects. IV. Rotating relativistic stars with mixed poloidal and toroidal magnetic fields
• Uniformly rotating, axisymmetric and triaxial quark stars in general relativity
• Conservation laws and evolution schemes in geodesic, hydrodynamic and magnetohydrodynamic flows
• Initial-data contribution to the error budget of gravitational waves from neutron-star binaries
• Evolution of bare quark stars in full general relativity: Single star case
• Do triaxial supramassive compact stars exist?
• Gravitational wave content and stability of uniformly, rotating, triaxial neutron stars in general relativity
• Equilibriums of extremely magnetized compact stars with force-free magnetotunnels
• Methods for relativistic self-gravitating fluids: From binary neutron stars to black hole-disks and magnetized rotating neutron stars
• Quasi-equilibrium models of magnetized compact objects
• The Parallel Compact Object CALculator: An Efficient General Relativistic Initial Data Solver for Compact Objects
• General Relativistic Stability and Gravitational Wave Content of Rotating Triaxial Neutron Stars