Resolving Massive Black Hole Binary Evolution via Adaptive Particle Splitting

The study of the interaction a massive black hole binary with its gaseous environment is crucial in order to be able predict merger rates and possible electromagnetic counterparts gravitational wave signals. evolution semi-major axis resulting from this has been recently debated, clear consensus still missing, also because several numerical limitations, i.e. fixed orbit binaries or lack resolution inside cavity carved by circumbinary disc. Using on-the-fly particle-splitting 3D meshless code gizmo, we achieve hyper-Lagrangian resolution, which allows us properly resolve dynamics cavity, particular for first time discs that form around two components live surrounded locally isothermal We show decays very cold warm result intermediate regime strongly uenced disc viscosity as essentially regulates fraction mass contained well accreted binary. find balance between these quantities determine whether decreases time.