Τίτλος:
Black hole feeding and star formation in NGC1808
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
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
1 `' = 45 pc. Within it, we found a decoupled circumnuclear disk or
molecular torus of a radius of 0:13 `' = 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
similar to 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.
Συγγραφείς:
Audibert, A.
Combes, F.
Garcia-Burillo, S.
Hunt, L. and
Eckart, A.
Aalto, S.
Casasola, V
Boone, F.
Krips, M. and
Viti, S.
Muller, S.
Dasyra, K.
van der Werf, P.
Martin,
S.
Περιοδικό:
Chinese Astronomy and Astrophysics
Εκδότης:
EDP SCIENCES S A
Λέξεις-κλειδιά:
galaxies: active; galaxies: starburst; galaxies: kinematics and
dynamics; galaxies: ISM; galaxies: nuclei galaxies individual: NGC1808
DOI:
10.1051/0004-6361/202039886
