The Impact of Rotation on Cluster Dynamics.pdf

Massive Star Clusters 8 ASP Conference Series, Vol. 3 ×10 , 1999 A. Lan¸con and C.M. Boily, eds. The Impact of Rotation on Cluster Dynamics Christian M. Boily Astronomisches Rechen-Institut, Heidelberg, Germany; 0 and Observatoire Astronomique de Strasbourg, France 0 0 Abstract. The evolution of rotating, isolated clusters of stars up to 2 core-collapse is investigated with n-body numerical codes. The simula- b tions start off from axisymmetric generalisations of King profiles, with e F added global angular momentum. In this contribution we report on re- sults obtained for two sets of single-mass cluster simulations. These con- 3 2 firm the more rapid evolution of even mildly-rotating clusters. A model is presented with rotational energy comparable to ωCentauri’s; it reaches 1 core-collapse in less than half the time required for non-rotating clusters. v 8 2 4 2 0 1. Background 0 0 / Star clusters are self-gravitating Newtonian systems of choice where to brew h p complex gravitational dynamics (Meylan Heggie 1997 for a review). Observa- - tions of old, globular, stellar clusters have led to the formulation of spherically o symmetric dynamical models of equilibria. The most successful and universally r t studied one-integral spherical models are the King (1966) profiles. However, s a surveys of up to 100 Milky Way clusters have found