The central region of the Circinus Galaxy observed with ALMA

The distributions of carbon monoxide (CO, reflecting the presence of medium-density molecular gas), atomic carbon (C, reflecting the presence of the atomic gas), hydrogen cyanide (HCN, reflecting the presence of high-density molecular gas), and the hydrogen recombination line (H36α; reflecting the presence of ionized gas), are shown in red, blue, green, and pink, respectively. There is an active galactic nucleus at the center. This galaxy is known to have a tilted structure from the outer to the inner regions, with the central region resembling a nearly edge-on disk. The size of the central dense gas disk (green) is approximately six light-years: this has been observed thanks to the high resolution of ALMA (see the inset for the zoom-up view). The plasma outflow travels almost perpendicular to the central dense disk.
Credit: ALMA (ESO/NAOJ/NRAO), T. Izumi et al.