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Black Hole-Neutron Star Binaries in General Relativity: Quasiequilibrium Formulation

Thomas W. Baumgarte·Monica L. Skoge·Stuart L. Shapiro
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Abstract

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 with the Euler equation for the neutron star matter. We take the system to be stationary in a corotating frame and thereby assume the presence of a helical Killing vector. We solve these coupled equations in the background metric of a Kerr-Schild black hole, which accounts for the neutron star's black hole companion. In this paper we adopt a polytropic equation of state for the neutron star matter and assume large black hole--to--neutron star mass ratios. These simplifications allow us to focus on the construction of quasiequilibrium neutron star models in the presence of strong-field, black hole companions. We summarize the results of several code tests, compare with Newtonian models, and locate the onset of tidal disruption in a fully relativistic framework.

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Thomas W. Baumgarte, Monica L. Skoge, Stuart L. Shapiro. 2004-07-20. Black Hole-Neutron Star Binaries in General Relativity: Quasiequilibrium Formulation. https://doi.org/10.1103/physrevd.70.064040

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