10 pc Scale Circumnuclear Molecular Gas Imaging of Nearby AGNs
  We present the images and kinematics of circumnuclear molecular gas from 100
pc scale down to 10 pc scale in nearby active galactic nuclei (AGNs) using the
Submillimeter Array (SMA) and the Plateau de Bure Interferometer (PdBI). We
have observed several nearby galaxies that host AGNs, such as the nearest radio
galaxy Centaurus A (NGC 5128), the Seyfert 2 galaxy M51 (NGC 5194), the Seyfert
2 galaxy NGC 1068, the Seyfert 1 galaxy NGC 1097, and the Seyfert 2 / starburst
composite galaxy NGC 4945, in CO lines to see whether the molecular gas
distribution, kinematics, and physical conditions at 10 - 100 pc scale follows
the AGN unified model or not. In 100 pc scale, most of the circumnuclear
molecular gas shows smooth velocity gradient, suggesting a regular rotating
feature, and also shows abnormal line ratios, suggesting the existence of
active sources to make the circumnuclear molecular gas dense and/or warm
conditions or abnormal chemical compositions. In 10 pc scale, on the other
hand, the molecular gas kinematics shows various characteristics, some shows
very disturbed kinematics such as a jet-entrained feature in the galaxies that
have jets, but some still shows regular rotation feature in a galaxy that does
not have obvious jets. These results indicate that the kinematics and
physical/chemical conditions of the circumnuclear molecular gas at the scale
less than 100 pc is highly affected by the AGN activities, and at this scale,
there is no clear evidence of any unified feature seen in the circumnuclear
molecular gas.
