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Related papers: Binary Neutron Stars in General Relativity: Quasi-…

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We present a new numerical method for the construction of quasiequilibrium models of black hole-neutron star binaries. We solve the constraint equations of general relativity, decomposed in the conformal thin-sandwich formalism, together…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Thomas W. Baumgarte , Monica L. Skoge , Stuart L. Shapiro

We report work towards a relativistic formulation for modeling strongly magnetized neutron stars, rotating or in a close circular orbit around another neutron star or black hole, under the approximations of helical symmetry and ideal MHD.…

General Relativity and Quantum Cosmology · Physics 2011-11-08 Charalampos Markakis , Koji Uryu , Eric Gourgoulhon

A general relativistic version of the Euler equation for perfect fluid hydrodynamics is applied to a system of two neutron stars orbiting each other. In the quasi-equilibrium phase of the evolution of this system, a first integral of motion…

General Relativity and Quantum Cosmology · Physics 2009-10-30 S. Bonazzola , E. Gourgoulhon , J. -A. Marck

Two relations, the virial relation $M_{\rm ADM}=M_{\rm K}$ and the first law in the form $\delta M_{\rm ADM}=\Omega \delta J$, should be satisfied by a solution and a sequence of solutions describing binary compact objects in…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Masaru Shibata , Koji Uryu , John L. Friedman

We construct relativistic equilibrium models of differentially rotating neutron stars and show that they can support significantly more mass than their nonrotating or uniformly rotating counterparts. We dynamically evolve such…

Astrophysics · Physics 2011-05-05 Thomas W. Baumgarte , Stuart L. Shapiro , Masaru Shibata

We report on the first calculations of fully relativistic binary circular orbits to span a range of separation distances from the innermost stable circular orbit (ISCO), deeply inside the strong field regime, to a distance ($\sim$ 200 km)…

General Relativity and Quantum Cosmology · Physics 2011-07-19 P. Marronetti , G. J. Mathews , J. R. Wilson

We present our study of stability of differentially rotating, axisymmetric neutron stars described by a polytropic equation of state with $\Gamma = 2$. We focus on quasi-toroidal solutions with a degree of differential rotation $\widetilde…

High Energy Astrophysical Phenomena · Physics 2024-02-29 Paweł Szewczyk , Dorota Gondek-Rosińska , Pablo Cerdá-Durán

Quasiequilibrium sequences of binary neutron stars are numerically calculated in the framework of the Isenberg-Wilson-Mathews (IWM) approximation of general relativity. The results are presented for both rotation states of synchronized…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Keisuke Taniguchi , Eric Gourgoulhon

We study the solution space of general relativistic, axisymmetric, equilibria of differentially rotating neutron stars with realistic, nuclear equations of state. We find that different types of stars, which were identified by earlier works…

High Energy Astrophysical Phenomena · Physics 2019-05-08 Pedro Espino , Vasileios Paschalidis

Solving dynamical problems in general relativity requires the full machinery of numerical relativity. Wilson has proposed a simpler but approximate scheme for systems near equilibrium, like binary neutron stars. We test the scheme on…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Gregory B. Cook , Stuart L. Shapiro , Saul A. Teukolsky

We propose a new numerical method to compute quasi-equilibrium sequences of general relativistic irrotational binary neutron star systems. It is a good approximation to assume that (1) the binary star system is irrotational, i.e. the…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Koji Uryu , Yoshiharu Eriguchi

Neutron star binaries offer a rich phenomenology in terms of gravitational waves and merger remnants. However, most general relativistic studies have been performed for nearly circular binaries, with the exception of head-on collisions. We…

General Relativity and Quantum Cosmology · Physics 2013-01-10 Roman Gold , Sebastiano Bernuzzi , Marcus Thierfelder , Bernd Bruegmann , Frans Pretorius

We investigate close binary neutron stars in quasiequilibrium states in a general relativistic framework. We assume conformal flatness for the spatial metric and irrotational velocity field for the neutron stars. We adopt the polytropic…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Koji Uryu , Masaru Shibata , Yoshiharu Eriguchi

We present the first computations of quasiequilibrium binary neutron stars with different mass components in general relativity, within the Isenberg-Wilson-Mathews approximation. We consider both cases of synchronized rotation and…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Keisuke Taniguchi , Eric Gourgoulhon

Outcomes of numerical relativity simulations of massive core collapses or binary neutron star mergers with moderate masses suggest formations of rapidly and differentially rotating neutron stars. Subsequent fall back accretion may also…

High Energy Astrophysical Phenomena · Physics 2017-11-29 Koji Uryu , Antonios Tsokaros , Luca Baiotti , Filippo Galeazzi , Keisuke Taniguchi , Shin'ichirou Yoshida

We present new sequences of general relativistic, quasiequilibrium black hole-neutron star binaries. We solve for the gravitational field in the conformal thin-sandwich decomposition of Einstein's field equations, coupled to the equations…

Astrophysics · Physics 2009-11-11 Keisuke Taniguchi , Thomas W. Baumgarte , Joshua A. Faber , Stuart L. Shapiro

A solution to an equilibrium of irrotational binary polytropic stars in Newtonian gravity is expanded in a power of \epsilon=a_0/R, where R and a_0 are the separation of the binary system and the radius of each star for R=\infty. For the…

Astrophysics · Physics 2009-10-31 Keisuke Taniguchi , Takashi Nakamura

In general neutron stars in binaries are spinning. Due to the existence of millisecond pulsars we know that these spins can be substantial. We argue that spins with periods on the order a few dozen milliseconds could influence the late…

General Relativity and Quantum Cosmology · Physics 2011-08-11 Wolfgang Tichy

Information about the last stages of a binary neutron star inspiral and the final merger can be extracted from quasi-equilibrium configurations and dynamical evolutions. In this article, we construct quasi-equilibrium configurations for…

We have designed and tested a new relativistic Lagrangian hydrodynamics code, which treats gravity in the conformally flat approximation to general relativity. We have tested the resulting code extensively, finding that it performs well for…

Astrophysics · Physics 2008-11-26 Joshua Faber , Philippe Grandclément , Frederic Rasio