SCYON Abstract

Received on April 30 2008

A Hybrid N-Body Code Incorporating Algorithmic Regularization and Post-Newtonian Forces

Authors	Stefan Harfst (¹), Alessia Gualandris (²), David Merritt (²), and Seppo Mikkola (³)
Affiliation	(¹) Astronomical Institute 'Anton Pannekoek', University of Amsterdam, the Netherlands (²) CCRG, Rochester Institute of Technology, Unites States (³) Tuorla Observatory, Turku University, Finland
Accepted by	Monthly Notices of the Royal Astronomical Society
Contact	harfst@science.uva.nl
URL	http://arxiv.org/abs/arXiv:0803.2310
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Abstract

We describe a novel N-body code designed for simulations of the central regions of galaxies containing massive black holes. The code incorporates Mikkola's 'algorithmic' chain regularization scheme including post-Newtonian terms up to PN2.5 order. Stars moving beyond the chain are advanced using a fourth-order integrator with forces computed on a GRAPE board. Performance tests confirm that the hybrid code achieves better energy conservation, in less elapsed time, than the standard scheme and that it reproduces the orbits of stars tightly bound to the black hole with high precision. The hybrid code is applied to two sample problems: the effect of finite-N gravitational fluctuations on the orbits of the S-stars; and inspiral of an intermediate-mass black hole into the galactic center.