The dynamical evolution of tidal capture binaries

Abstract

Three new considerations are introduced into the evolution of tidal capture binaries: the evolution of the structure and the dynamical stability of the star, the stochasticity of the evolution due to the proper addition of mode amplitudes, and the role of the local environment in altering the energy and angular momentum distribution of the resultant binaries. Following the first encounter, a main-sequence star is well modeled by an irrotational Reimann ellipsoid, a triaxial configuration with no vorticity. Viscosity is found to be critical to understanding the evolution of these systems, because viscosity regulates the growth of oscillations and the amount of damage done to the star. The results of tidal captures are sensitive to the properties of the global cluster through the density of the local environment and the typical mass of the main-sequence star.