Closing the feedback-feeding loop of the radio galaxy 3C 84

Gas accretion by a galaxy's central supermassive black hole (SMBH) and the resultant energetic feedback by the accreting active galactic nucleus (AGN) on the gas in and around a galaxy are two tightly intertwined but competing processes that play a crucial role in the evolution of galaxies. Observations of galaxy clusters have shown how the plasma jets emitted by an AGN heat the intracluster medium, preventing cooling of the cluster gas and thereby the infall of this gas onto the central galaxy. On the other hand, outflows of multiphase gas, driven by the jets, can cool as they rise into the intracluster medium, leading to filaments of colder gas. The fate of this cold gas is unclear, but it has been suggested that it plays a role in feeding the central SMBH. We present the results of reprocessed CO(2-1) Atacama Large Millimeter/submillimeter Array observations of the cold molecular gas in the central regions of NGC 1275, the central galaxy of the Perseus cluster and which hosts the radio-loud AGN 3C 84 (Perseus A). These data show in detail how kiloparsec-sized cold gas filaments resulting from the jet-induced cooling of cluster gas are flowing towards the galaxy centre and how they feed the circum-nuclear accretion disk (100 pc diameter) of the SMBH. Thus, cooled gas can, in this way, play a role in feeding the AGN. These results complete our view of the feedback loop of how an AGN can impact its surroundings and how the effects of this impact maintain the AGN activity.