ALMA resolves the torus of NGC 1068: Continuum and molecular line emission
Journal article, 2016
We used the Atacama Large Millimeter Array (ALMA) to map the emission of the CO(6-5) molecular line and the 432 mu m continuum emission from the 300 pc sized circumnuclear disk (CND) of the nearby Seyfert 2 galaxy NGC 1068 with a spatial resolution of similar to 4 pc. These observations spatially resolve the CND and, for the first time, image the dust emission, the molecular gas distribution, and the kinematics from a 7-10 pc diameter disk that represents the submillimeter counterpart of the putative torus of NGC 1068. We fitted the nuclear spectral energy distribution of the torus using ALMA and near-and mid-infrared (NIR/MIR) data with CLUMPY torus models. The mass and radius of the best-fit solution for the torus are both consistent with the values derived from the ALMA data alone: M-gas(torus) = (1 +/- 0.3) x 10(5) M-circle dot and R-torus = 3.5 +/- 0.5 pc. The dynamics of the molecular gas in the torus show strong non-circular motions and enhanced turbulence superposed on a surprisingly slow rotation pattern of the disk. By contrast with the nearly edge-on orientation of the H2O megamaser disk, we found evidence suggesting that the molecular torus is less inclined (i = 34 degrees-66 degrees) at larger radii. The lopsided morphology and complex kinematics of the torus could be the signature of the Papaloizou-Pringle instability, long predicted to likely drive the dynamical evolution of active galactic nuclei tori.
galaxies: kinematics and dynamics
galaxies: Seyfert
galaxies: individual (NGC 1068)
galaxies: ISM
galaxies: nuclei
Author
S. G. Burillo
Spanish National Observatory (OAN)
F. Combes
Collège de France
C. R. Almeida
Instituto de Astrofísica de Canarias
University of La Laguna
A. Usero
Spanish National Observatory (OAN)
M. Krips
Institut de Radioastronomie Millimétrique (IRAM)
A. Alonso-Herrero
Centro de Astrobiologia (CAB)
Susanne Aalto
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
V. Casasola
Arcetri Astrophysical Observatory
L. K. Hunt
Arcetri Astrophysical Observatory
S. Martin
Atacama Large Millimeter-submillimeter Array (ALMA)
European Southern Observatory Santiago
S. Viti
University College London (UCL)
L. Colina
Universidad Autonoma de Madrid (UAM)
Centro de Astrobiologia (CAB)
Francesco Costagliola
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
A. Eckart
University of Cologne
A. Fuente
Spanish National Observatory (OAN)
C. Henkel
Max Planck Society
King Abdulaziz University
I. Marquez
Spanish National Research Council (CSIC)
R. Neri
Institut de Radioastronomie Millimétrique (IRAM)
E. Schinnerer
Max Planck Society
L. J. Tacconi
Max Planck Society
P.P. van der Werf
Leiden University
Astrophysical Journal Letters
2041-8205 (ISSN) 2041-8213 (eISSN)
Vol. 823 1 Art. no. L12- L12Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
DOI
10.3847/2041-8205/823/1/l12