The Discovery of an Active Wind from the Milky Way’s Central Black Hole

Abstract Every large galaxy has a black hole in its center. The interaction between the black hole and its host profoundly shapes galactic evolution and the Universe as a whole. The key features of this interaction are black hole jets—or more generally, winds—which every black hole must have. Despite the proximity and importance of our Galaxy’s central black hole, Sagittarius A* (Sgr A*), the active wind from it has eluded scientists for over half a century. Here we report the discovery of a large active wind from Sgr A* using unprecedentedly deep ( T b ∼ 30 mK) and high angular resolution (≲0 . ″ 25) observations with the Atacama Large Millimeter/Submillimeter Array (ALMA). We detect a large conical clearing in the cold molecular gas surrounding Sgr A* that is at least 1 parsec long and has a ∼45° opening angle. The morphology and energetics of this structure are consistent with active clearing of gas by a hot wind from Sgr A*.