A Hybrid N-Body Code incorporating algorithmic regularization and Post-Newtonian forces
Date
2008-07-24Author
Harfst, Stefan
Gualandris, Alessia
Merritt, David
Seppo, Mikkola
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Show full item recordAbstract
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 in spiral of an intermediate mass
black hole into the galactic center.