Speaker
Description
Three-body interactions play a dominant role in the evolution of dense stellar systems, such as clusters, and in particular in the dynamical formation of gravitational-wave sources. Indeed, one of the channels for binary formation during cluster core collapse is via the "collision" of three initially-unbound objects. In this talk I will describe an analytical formalism to calculate the properties of such three-body binaries, including their non-thermal eccentricity distribution and their formation rate, based on a probabilistic analysis of unbound three-body encounters, and discuss some implications for the population of eccentric, wide binaries observed by Gaia. This approach can model general binary-single encounters between hard binaries and single stars, and I will describe how to do so. Hard binaries go on to harden via subsequent three-body encounters, and I will also model the evolution of their properties under such interactions, which gives rise to a unique eccentricity distribution.
