Criteria of Dynamical Isolation of Binaries and Multiples

Abstract

In order to obtain an objective criterion for dynamical isolation of binaries within systems of large multiplicity we study numerically the dynamical behavior and average parameters of stable hierarchical triple systems con taining a close binary. Using the new criterion for hierarchical stability of triple systems with different mass ratios of components (Kiseleva, Eggleton, Anosova 1994; Kiseleva, Eggleton, Orlov 1994) the perturbing force from the outer body on the close inner binary is estimated. On this basis, the critical separations are obtained when both inner and outer orbits are practically not perturbed. Because the dispersion of masses has a very strong influence on dynamical processes in N-body systems, mass ratios of subsystems, and sometimes within subsystems, should always be taken into account.