Direct Simulations of Astrophysical Many-Body Systems (Star Clusters, Dense Stellar
Systems around Massive Black Holes)
In these simulations a large number of particles (namely the stars) interact only by their
gravitational force. Relaxation and heat conduction, provided by the cumulative effect of
small-angle two-body encounters between particles, compete with external influences such as
the gravity of a supermassive black hole of a few million solar masses,
as has been detected at
the center of our Milky Way. In this example, we followed a star cluster, similar to
a globular cluster, as it approaches the central parsec of our Milky Way, is deformed by tidal
forces of the central black hole (first picture) and is finally distorted
into a spiral configuration
of tidal arms with the supermassive black hole (second picture, black hole not highlighted but
its position can be inferred from the convergence point of the two spiral arms). These figures
are snapshots from a movie produced using the special interface of the VISIT software of NIC
Jülich for our N-body simulation codes. The pictures contain a color code depicting the local
stellar density, and small velocity arrows highlighting the velocities of individual stars. To
avoid overcrowding of the picture not all stars were plotted. In other simulations, we use
similar methods to study the evolution of binary supermassive black holes embedded in dense
stellar clusters (with possible generation of gravitational waves due to merging of the two
black holes), and also the stability and formation of extrasolar planetary systems.
(Rainer Spurzem, Gabor Kupi, Patrick Glaschke, Christoph Eichhorn, Astronomisches
Rechen-Institut, Heidelberg; Chingis Omarov, Fessenkov Observatory, Almaty Kazakhstan)
Sabine Höfler-Thierfeldt