An N-body simulation of a gravothermal expansion

This paper describes results of an N-body computation which was designed to show whether or not gravothermal expansion occurs in the presence of fluctuations. The initial conditions were chosen to mimic the density and velocity dispersion profiles of a fluid cluster model during a gravothermal expansion. On the time-scale of the simulation the evolution of the mass distribution of the N-body model qualitatively resembles that of a fluid model, though the expansion of the core is twice as fast. The N-body model also exhibits phenomena which are not found in the fluid model: motions of the core with an amplitude exceeding a core radius, and, at all radii, persistent radial oscillations on a orbital timescale. (author)