The nuclear star cluster


Mass and distance constraints of Sgr A* from the S2 orbit (blue) and from a dynamical model of the nuclear cluster (red). The combined constraint is given by the black contours.

Our long-term monitoring of the Galactic Center region with NACO and SINFONI has led to a very valuable data base of stellar motions: We have measured proper motions for more than 10000 stars and radial velocities for almost 3000 stars (Fritz et al. 2016). Together with the density profile, we can determine the dynamic configuration of the nuclear cluster (Chatzopoulos et al. 2015). This allows measuring completely independent from the stellar orbits the mass of the central point source, the distance to the system, and the mass profile of the extended cluster.





Mass of and distance to Sgr A* are consistent with our results from the stellar orbits. The mass profile shows that massive black hole dominates the mass in the central parsec.


The mass profile in the Galactic Center, derived from dynamical modeling of the large data set of stellar motions and the observed mass profile.

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