Virgo high-resolution CO survey: V. Circumnuclear elliptical ring in NGC 4569

We present high-resolution (1.″8-4.″5) CO data of the Virgo spiral galaxy NGC 4569, obtained using the Nobeyama Millimeter Array. We found that the molecular gas is highly concentrated in the circumnuclear region with two off-center peaks. A CO image with the highest angular resolution of 2.″0 × 1.″8 shows that six blobs likely form a circumnuclear elliptical ring (CER) with a semimajor axis of 720 pc. The CER shows a strongly twisted velocity field, and the position-velocity diagram shows significant forbidden velocity components. These kinetic features are understood as being non-circular motion due to a bar-potential. We found that the CER coincides with the Ha bright central core and that the mass ratio of the molecular gas to the dynamical mass is about 18%. These results support a gaseous inflow scenario induced by a weak bar potential and self-gravity of the gas.