The Slingshot Revisited

Abstract

(Abridged) In this celebratory contribution, we present some new data from standard star cluster modelling containing primordial binaries and triples, as well as results from a binary black hole simulation with two massive members. In the star cluster case, the process of mass loss from evolving stars, together with general mass segregation, promotes favourable interactions involving compact subsystems of binaries and triples in the central region. Three-body interactions often lead to energetic ejections, with one or more of the components attaining relatively large terminal velocities which can be observed in principle. The second type of stellar system to be discussed is based on the scenario of two approaching galactic cores with density cusps, each having a massive black hole. After the subsystems become well mixed, the two massive components soon form a hard binary which gains energy by ejecting other members. Such a massive binary has a large cross section and can be very effective in depleting bound stars from the core. Again high-velocity escapers are produced, with their terminal speeds related to the shrinking binary size which eventually leads to coalescence.