INITIAL CONDITIONS AND DYNAMICS OF TRIPLE-SYSTEMS

The dynamical evolution of triple systems with equal-mass components a nd zero initial velocities is studied. We consider two regions of init ial conditions: a region D of all possible configurations of triples a nd a circle R. The configurations are distributed uniformly within the se regions. The calculations have been carried out until a time when e scape or 'conditional' escape (i.e. distant ejection) of one component takes place. The accuracy has been checked by doing time-reversed int egration. Types of 'predictable' and 'non-predictable' systems are rev ealed. Averages for a number of evolution parameters are presented: th e life-time, minimum perimeter during the last triple approach resulti ng in escape, semi-major axis and eccentricity of the final binary, an d the smallest separation between the components during the evolution. It is shown that the statistical results for the regions D and R do n ot differ significantly for the most part. Our results, which have bee n obtaned by a three-body regularization method, are in good agreement with previous work based on the RK4 integrator and Sundman's time smo othing.