https://www.nature.com/articles/s41550-017-0224-z
The kinematical structure of CO–0.40–0.22 can be explained as being due to a gravitational kick experienced by the molecular cloud caused by an invisible compact object with a mass of about 10^5M⊙. The compactness and absence of a counterpart at other wavelengths suggest that this massive object is an inactive IMBH, which is not currently accreting matter. This is the second-largest black hole candidate in the Milky Way galaxy after Sgr A*, as well as the second IMBH candidate in the Galaxy after that in the nuclear subcluster IRS13E (MBH ≈ 1,300M⊙).