Numerical Models of Binary Neutron Star System Mergers. I.: Numerical Methods and Equilibrium Data for Newtonian Models

Abstract

The numerical modeling of binary neutron star mergers has become a subject of much interest in recent years. While a full and accurate model of this phenomenon would require the evolution of the equations of relativistic hydrodynamics along with the Einstein field equations, a qualitative study of the early stages on inspiral can be accomplished by either Newtonian or post-Newtonian models, which are more tractable. In this paper we offer a comparison of results from both rotating and non-rotating (inertial) frame Newtonian calculations. We find that the rotating frame calculations offer significantly improved accuracy as compared with the inertial frame models. Furthermore, we show that inertial frame models exhibit significant and erroneous angular momentum loss during the simulations that leads to an unphysical inspiral of the two neutron stars. We also examine the dependence of the models on initial conditions by considering initial configurations that consist of spherical neutron stars as well as stars that are in equilibrium and which are tidally distorted. We compare our models those of Rasio & Shapiro (1992,1994a) and New & Tohline (1997). Finally, we investigate the use of the isolated star approximation for the construction of initial data.

32 pages, 19 gif figures, manuscript with postscript figures available at http://www.astro.sunysb.edu/dswesty/docs/nspap1.ps

References in corpus (4)

• Discovery of the X-Ray Afterglow of the Gamma-Ray Burst of February 28 1997
• Gravitational Radiation from the Coalescence of Binary Neutron Stars: Effects Due to the Equation of State, Spin, and Mass Ratio
• The Relative Stability Against Merger of Close, Compact Binaries
• Numerical Models of Binary Neutron Star System Mergers. I.: Numerical Methods and Equilibrium Data for Newtonian Models

Cited by in corpus (14)

• Binary Neutron Star Mergers
• Surface Detonations in Double Degenerate Binary Systems Triggered by Accretion Stream Instabilities
• Coalescing neutron stars - a step towards physical models III. Improved numerics and different neutron star masses and spins
• Numerical Simulations of the Onset and Stability of Dynamical Mass Transfer in Binaries
• Hydrodynamic Simulations in 3+1 General Relativity
• Numerical Methods for the Simulation of Dynamical Mass Transfer in Binaries
• Post-Newtonian SPH calculations of binary neutron star coalescence. II. Binary mass ratio, equation of state, and spin dependence
• Dynamical Determination of the Innermost Stable Circular Orbit of Binary Neutron Stars
• White Dwarf Mergers on Adaptive Meshes I. Methodology and Code Verification
• Post-Newtonian SPH calculations of binary neutron star coalescence. III. Irrotational systems and gravitational wave spectra
• Numerical Models of Binary Neutron Star System Mergers. I.: Numerical Methods and Equilibrium Data for Newtonian Models
• Hamiltonian Relaxation
• Gravitational and electromagnetic emission by magnetized coalescing binary systems
• Momentum constraint relaxation