Molecular Gas Dynamics in NGC 6946: a Bar-driven Nuclear Starburst "Caught in the Act" Shinnerer, E. Böker, Torsten Emsellem, E. Lisenfeld , Ute Galaxies NGC 6946 ISM Kinematics and dynamics Nuclei We present high angular resolution ~1" and 0.6" mm-interferometric observations of the 12CO(1-0) and 12CO(2-1) line emission in the central 300pc of the late-type spiral galaxy NGC6946. The data, obtained with the IRAM Plateau de Bure Interferometer (PdBI), allow the first detection of a molecular gas spiral in the inner ~10" (270pc) with a large concentration of molecular gas (M(H_2) ~1.6x10^7M_sun) within the inner 60pc. This nuclear clump shows evidence for a ring-like geometry with a radius of ~10pc as inferred from the p-v diagrams. Both the distribution of the molecular gas as well as its kinematics can be well explained by the influence of an inner stellar bar of about 400pc length. A qualitative model of the expected gas flow shows that streaming motions along the leading sides of this bar are a plausible explanation for the high nuclear gas density. Thus, NGC6946 is a prime example of molecular gas kinematics being driven by a small-scale, secondary stellar bar. 2013-10-10T12:34:23Z 2013-10-10T12:34:23Z 2006 preprint Shinnerer, E.; et al. Molecular Gas Dynamics in NGC 6946: a Bar-driven Nuclear Starburst "Caught in the Act". Astrophysical Journal, 649(1): 181-200 (2006). [http://hdl.handle.net/10481/28414] 0004-637X 1538-4357 arXiv:astro-ph/0605702v2 http://hdl.handle.net/10481/28414 10.1086/506265 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ open access Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License American Astronomical Society; Institute of Physics (IOP)