Sketch of principal system components and initial parameters. S and N BHs are represented by large red and blue dashed dots respectively and placed at an initial separation of ΔR. Black holes have initial velocities V₁ and V₂, for S and N nuclei respectively. Bulges around nuclei have sizes r₁ and r₂ (each size is equal to 5 Plummer radii of the corresponding bulge), and consist of high-mass particles and low-mass particles, and are represented by purple and green dots respectively.