2012ApJ...756..195L

The supermassive black hole (SMBH), Sgr A*, at the Galactic center is surrounded by a molecular circumnuclear disk (CND) lying between 1.5 and 4 pc radii. The irregular and clumpy structures of the CND suggest dynamical evolution and episodic feeding of gas toward the central SMBH. New sensitive data from the Submillimeter Array and Green Bank Telescope reveal several >5-10 pc scale molecular arms, which either directly connect to the CND or may penetrate inside the CND. The CND appears to be the convergence of the innermost parts of large-scale gas streamers, which are responding to the central gravitational potential well. Rather than being a quasi-stationary structure, the CND may be dynamically evolving, incorporating inflow via streamers, and feeding gas toward the center.