To date, the growth mechanism of supermassive black holes (SMBHs) is a scientific mystery. If we consider the accretion rate of the SMBH in our Milky Way, Sagittarius A* (Sgr A*), and the age of the universe, a discrepancy of several magnitudes in its mass opens up. One proposed idea to overcome the mismatch of accretion rate and age of the universe is merging events between intermediate-mass black holes (IMBHs) that ultimately form SMBHs. However, only around 10 IMBHs in our entire universe have been confirmed by observations, which poses a significant challenge to the theory of merging black holes. In Peißker et al. (2023c) and Peißker et al. (2024b), we have analyzed the densest stellar cluster, IRS 13, in our Milky Way, only about 0.3 lightyears away from Sgr A*. This massive embedded cluster shows two distinct generations of stars, implying independent and plausible triggered, star formation events. Until recently, it was unclear how and why this cluster so close to an SMBH seems to preserve its shape. As we show in both related publications, the cluster comprises three distinctive components. One of the components is associated with the dense core of the cluster, whereas the other one shows signs of evaporation. We argue that IRS 13 is the remanent of a more massive cluster that plunges into the gravitational well of our central SMBH. One key aspect of this analysis is the young age of the two stellar populations. From the young age and plausible star formation channels, we derive an unusually short cluster migration timescale. One explanation for the rapid infall of the cluster could be the presence of an IMBH inside the cluster. In Peißker et al. (2024b), we confirm that the presence of an IMBH is highly likely. Due to the evaporation nature of the cluster, it is expected that we identified one of the first pre-merger setups between an SMBH and IMBH to date.
