2015ApJ...806..220A

The central region of the galaxy Henize 2-10 hosts a black hole (BH) candidate with a mass Log(M_BH/M_☉) = 6.3 ± 1.1. While this putative BH does not appear to coincide with any central stellar overdensity, it is surrounded by 11 young massive clusters with masses above 10⁵ M_☉. The availability of high-quality data on the structure of the galaxy and the age and mass of the clusters provides excellent initial conditions for studying the dynamical evolution of Henize 2-10's nucleus. Here we present a set of N-body simulations in which we model the future evolution of the central clusters and the BH to understand whether and how they will merge to form a nuclear star cluster (NSC). NSCs are present in a majority of galaxies with stellar mass similar to Henize 2-10. While the results depend on the choice of initial conditions, we find that an NSC with mass M_NSC ~= 4-6 x 10⁶M_☉ and effective radius r_NSC ~= 2.6 -4.1 pc will form within 0.2 Gyr. This work is the first showing, in a realistic realization of the host galaxy and its star cluster system, that the formation of a bright nucleus is a process that can happen after the formation of a central massive BH leading to a composite NSC+BH central system. The cluster merging process does not significantly affect the kinematics of the BH; when a stationary state is reached, its position changes by ≲ 1 pc and its velocity by < 2 km/s.