2019ApJ...871L...1T

We report the discovery of molecular gas streams orbiting around an invisible massive object in the central region of our Galaxy, based on the high-resolution molecular line observations with the Atacama Large Millimeter/submillimeter Array. The morphology and kinematics of these streams can be reproduced well through two Keplerian orbits around a single point mass of (3.2 ± 0.6) x 10⁴ M_☉. We also found ionized gas toward the inner part of the orbiting gas, indicating dissociative shock and/or photoionization. Our results provide new circumstantial evidences for a wandering intermediate-mass black hole in the Galactic center, suggesting also that high-velocity compact clouds can be probes of quiescent black holes that abound in our Galaxy.