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The Kinematics and Distribution of the Molecular Gas in the Circumnuclear Region of NGC 7469

L.J. Tacconi, R. Genzel, L.E. Tacconi-Garman, and J.F. Gallimore
Max-Planck-Institut für extraterrestrische Physik, Postfach 1603, D-85740 Garching, Germany
Abstract: We have made a CO J=10 map of the Seyfert 1 galaxy, NGC 7469 at 2.5 spatial resolution with the IRAM millimeter interferometer. The high signal-to-noise ratio of these data and the spectral resolution of 10 km s have allowed us to glean kinematic details on spatial scales smaller than this (see Figure). From model fits we find that the molecular gas comes from a combination of a 1.5 radius circumnuclear ring and a central gas concentration associated with the narrow line region (NLR). This structure is very similar to the molecular structure seen in the Seyfert 2 galaxy NGC 1068, and is consistent with current unified schemes for Seyfert galaxies. The velocity distribution has a slowly rising (not solid-body) rotation curve. The gas lies in a plane with a low inclination angle of 25. These kinematic parameters imply a dynamical mass of 2.010 M in the central 5 (1.6 kpc), with the molecular mass dominating the dynamical mass. The dynamical measurements thus allow a calibration of the H--to--CO conversion factor in a Seyfert galaxy. We find that the NGC 7469 conversion factor is 1.5 times the Galactic value.