According to the standard LCDM model, the globular clusters (GCs) of the Milky Way (MW) are the first gravitationally bound stellar systems to form in the early Universe, with a typical age of about 10-12 billion years. GCs are quite common in the Galaxy. In early 2020, 150 of them were found in the MW, in 2022 - 160, and more than 10 stellar systems are candidates for GCs. In the past few...
The Galactic center region has a mass of ~10^9 M_sun. It consists of the nuclear stellar disk (NSD), a flat, rotating stellar structure, and the nuclear star cluster (NSC), the densest concentration of stars in the Galaxy.
The NSC and NSD are distinct structures of the Milky Way, but also connected to the larger Milky Way structures, e.g. via the inflow and outflow of gas, and the infall of...
The nuclear star cluster (NSC) of the Milky Way has been extensively studied in the last decades, using ground-based astrometry and spectroscopy of ~10000 stars in the inner 10 pc.
The Galactic centre is unique in that we have a direct measurement of the mass of the supermassive black hole (SMBH) from the motion of S-stars, which can be tracked for a significant fraction of the orbital...
Since 2017, the GRAVITY interferometer at ESO's Very Large Telescope has allowed us to obtain astrometric data with unprecedented accuracy of the S-stars orbiting around Sagittarius A*, turning them into a powerful tool to investigate the gravitational potential around the supermassive black hole at the center of our Galaxy.
In particular, for the star S2, we have been able to detect the...
Recently the precession rate of S2 around the SMBH at the Galactic Center is reported (Abuter et al., 2020). At the same time, other astronomical and physical values, such as orbital elements of S2, mass of the central SMBH, the distance to it, parameters for GR effect and so on, are estimated.
From a theoretical point of view, Rauch & Tremaine (1996) predicted the precession of stars...
Galactic nuclei, the densest stellar environments in the Universe, exhibit a complex geometrical structure. The stars orbiting the central supermassive black hole follow a mass segregated distribution both in the radial distance from the center and in the inclination angle of the orbital planes. This distribution may represent the equilibrium state of vector resonant relaxation (VRR).
In...
