Black hole feeding and star formation in NGC 1808

Audibert, A.Observatoire de Paris,Paris Observatory,Instituto de Astrofísica de Canarias,National Observatory of Athens,Universidad de la Laguna,University of La Laguna (författare)

We report on Atacama Large Millimeter Array (ALMA) observations of CO(3-2) emission in the Seyfert2/starburst galaxy NGC1808, at a spatial resolution of 4 pc. Our aim is to investigate the morphology and dynamics of the gas inside the central 0.5 kpc and to probe the nuclear feeding and feedback phenomena. We discovered a nuclear spiral of radius 100 = 45 pc. Within it, we found a decoupled circumnuclear disk or molecular torus of a radius of 0:1300 = 6 pc. The HCN(4-3) and HCO+(4-3) and CS(7-6) dense gas line tracers were simultaneously mapped and detected in the nuclear spiral and they present the same misalignment in the molecular torus. At the nucleus, the HCN/HCO+ and HCN/CS ratios indicate the presence of an active galactic nucleus (AGN). The molecular gas shows regular rotation, within a radius of 400 pc, except for the misaligned disk inside the nuclear spiral arms. The computations of the torques exerted on the gas by the barred stellar potential reveal that the gas within a radius of 100 pc is feeding the nucleus on a timescale of five rotations or on an average timescale of 60 Myr. Some non-circular motions are observed towards the center, corresponding to the nuclear spiral arms. We cannot rule out that small extra kinematic perturbations could be interpreted as a weak outflow attributed to AGN feedback. The molecular outflow detected at 250 pc in the NE direction is likely due to supernovae feedback and it is connected to the kpc-scale superwind.

Combes, F.Collège de France,Observatoire de Paris,Paris Observatory (författare)
Burillo, S. G.Observatorio Astronómico Nacional (OAN),Spanish National Observatory (OAN) (författare)
Hunt, L. K.Osservatorio Astrofisico di Arcetri,Arcetri Astrophysical Observatory (författare)
Eckart, A.Universität zu Köln,University of Cologne (författare)
Aalto, Susanne,1964Chalmers tekniska högskola,Chalmers University of Technology(Swepub:cth)saalto (författare)
Casasola, V.Istituto di Radioastronomia (författare)
Boone, F.Institut de Recherche en Astrophysique et Planétologie (IRAP) (författare)
Krips, M.Institut de Radioastronomie Millimétrique (IRAM) (författare)
Viti, SerenaUniversity College London (UCL),Universiteit Leiden (UL),Leiden University (UL) (författare)
Muller, Sebastien,1976Chalmers tekniska högskola,Chalmers University of Technology(Swepub:cth)mullers (författare)
Dasyra, K. M.National Observatory of Athens,University of Athens (författare)
van der Werf, P.Universiteit Leiden (UL),Leiden University (UL) (författare)
Martin, S.European Southern Observatory Santiago,Atacama Large Millimeter-submillimeter Array (ALMA) (författare)
Observatoire de ParisInstituto de Astrofísica de Canarias (creator_code:org_t)

Av författaren/redakt...: Audibert, A.; Combes, F.; Burillo, S. G.; Hunt, L. K.; Eckart, A.; Aalto, Susanne, ...; visa fler...; Casasola, V.; Boone, F.; Krips, M.; Viti, Serena; Muller, Sebastie ...; Dasyra, K. M.; van der Werf, P.; Martin, S.; visa färre...

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