Molecular Gas in NUclei of GAlaxies (NUGA). X. The Seyfert 2 galaxy NGC 3147

We present 12CO(1-0) and 12CO(2-1) observations of the SA(rs)bc Seyfert 2 galaxy NGC 3147, obtained with the IRAM interferometer at 1.9′ x 1.6′′ and 1.6′′ x 1.4′′ resolutions, respectively. We have also observed the central region of NGC3147 with the IRAM 30m telescope (at resolutions of 22′′ and 12...

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Detalles Bibliográficos
Autores: Casasola, Viviana, Combes, F., García-Burillo, Santiago, Hunt, L. K., Léon, Stéphane, Baker, A. J.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2008
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/6876
Acceso en línea:http://hdl.handle.net/10261/6876
Access Level:acceso abierto
Palabra clave:Galaxies: individual: NGC3147
Galaxies: spiral
Galaxies: active
Galaxies: nuclei
Galaxies: ISM
Galaxies: kinematics and dynamics
Descripción
Sumario:We present 12CO(1-0) and 12CO(2-1) observations of the SA(rs)bc Seyfert 2 galaxy NGC 3147, obtained with the IRAM interferometer at 1.9′ x 1.6′′ and 1.6′′ x 1.4′′ resolutions, respectively. We have also observed the central region of NGC3147 with the IRAM 30m telescope (at resolutions of 22′′ and 12′′ for 12CO(1-0) and 12CO(2-1), respectively), in order to obtain complete sampling at low spatial frequencies. These observations have been made in the context of the NUclei of GAlaxies (NUGA) project, aimed at the study of the different mechanisms for gas fueling of active galactic nuclei (AGN). A central peak seen mainly in 12CO(2-1) and a ring-like structure at r ~ 10′′ ~ 2 kpc dominate the 12CO maps. In 12CO(1-0) an outer spiral at r ~ 20′′ ~ 4 kpc is also detected, not visible in 12CO(2-1) emission because it falls outside the field-of-view of the primary beam. The average I21/I10 line ratio is ∼ 0.7 in temperature units over the region mapped in both lines, consistent with the optically thick emission expected in the nuclei of spiral galaxies. The kinematics of the molecular structures are quite regular, although there is evidence for local non-circular or streaming motions. We show that the molecular gas distribution is similar but not exactly identical to those of star formation tracers, i.e., infrared (Spitzer) and ultraviolet (GALEX) emission. This agreement is consistent with a scenario of steady, ongoing formation of stars from the molecular clouds at a rate of ∼ 1 M⊙ yr−1 within the innermost 4 kpc in radius.