Time evolution simulations for the galactic centre circumnuclear disc

Abstract

The supermassive black hole at the Galactic Centre is surrounded by the so-called Circumnuclear Disc (CND) with a sharp inner edge at 1.5 pc. Both its outer extent and the total mass contained within it are somewhat unknown making it difficult to conclude on its long term stability. In this work we report the results of our simulations for the orbital evolution of the CND taking into account its warped shape, its self-gravity and the torques induced by the surrounding flattened nuclear star cluster. Assuming different values for the outer radius of the CND and different masses and flattening values for the star cluster we first find steadily precessing warped disc solutions for parameters relevant to the CND and the nuclear star cluster. In order to study the long term stability of the CND, we then follow the orbital evolution of the CND. Our results suggest that beyond 2 pc the CND is a stable structure on timescales of about a few Myr.