Bibcode
Alonso-Herrero, A.; García-Burillo, S.; Pereira-Santaella, M.; Davies, R. I.; Combes, F.; Vestergaard, M.; Raimundo, S. I.; Bunker, A.; Díaz-Santos, T.; Gandhi, P.; García-Bernete, I.; Hicks, E. K. S.; Hönig, S. F.; Hunt, L. K.; Imanishi, M.; Izumi, T.; Levenson, N. A.; Maciejewski, W.; Packham, C.; Ramos Almeida, C.; Ricci, C.; Rigopoulou, D.; Roche, P. F.; Rosario, D.; Schartmann, M.; Usero, A.; Ward, M. J.
Bibliographical reference
Astronomy and Astrophysics, Volume 628, id.A65, 17 pp.
Advertised on:
8
2019
Journal
Citations
52
Refereed citations
50
Description
ALMA observations have revealed nuclear dusty molecular disks or tori
with characteristic sizes 15-40 pc in the few Seyferts and low
-luminosity AGN that have been studied so far. These structures are
generally decoupled both morphologically and kinematically from the host
galaxy disk. We present ALMA observations of the CO(2-1) and CO(3-2)
molecular gas transitions and associated (sub-) millimeter continua of
the nearby Seyfert 1.5 galaxy NGC 3227 with angular resolutions 0.085 -
0.21″ (7-15 pc). On large scales, the cold molecular gas shows
circular motions as well as streaming motions on scales of a few hundred
parsecs that are associated with a large-scale bar. We fit the nuclear
ALMA 1.3 mm emission with an unresolved component and an extended
component. The 850 μm emission shows at least two extended
components, one along the major axis of the nuclear disk, and the other
along the axis of the ionization cone. The molecular gas in the central
region (1″ ˜ 73 pc) shows several CO clumps with complex
kinematics that appears to be dominated by noncircular motions. While we
cannot conclusively demonstrate the presence of a warped nuclear disk,
we also detected noncircular motions along the kinematic minor axis.
They reach line-of-sight velocities of v - vsys = 150 - 200
km s-1. Assuming that the radial motions are in the plane of
the galaxy, we interpret them as a nuclear molecular outflow due to
molecular gas in the host galaxy that is entrained by the AGN wind. We
derive molecular outflow rates of 5 M⊙ yr-1
and 0.6 M⊙ yr-1 at projected distances of up
to 30 pc to the northeast and southwest of the AGN, respectively. At the
AGN location we estimate a mass in molecular gas of 5 ×
105 M⊙ and an equivalent average column
density N(H2) = 2 - 3 × 1023 cm-2
in the inner 15 pc. The nuclear CO(2-1) and CO(3-2) molecular gas and
submillimeter continuum emission of NGC 3227 do not resemble the
classical compact torus. Rather, these emissions extend for several tens
of parsecs and appear connected with the circumnuclear ring in the host
galaxy disk, as found in other local AGN.
Related projects
Nuclear Activity in Galaxies: a 3D Perspective from the Nucleus to the Outskirts
This project consists of two main research lines. First, the study of quasar-driven outflows in luminous and nearby obscured active galactic nuclei (AGN) and the impact that they have on their massive host galaxies (AGN feedback). To do so, we have obtained Gran Telescopio CANARIAS (GTC) infrared and optical observations with the instruments
Cristina
Ramos Almeida