2006/05/30 by E. Schinnerer, Eva Schinnerer, T. Boeker +4 · 2 citations
Physics and Astronomy · #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/506265
published as Astrophys.J.649:181-200,2006 · accepted for publication in the Astrophysical Journal; 47 pages, 17 figures, 1 table
arxiv created 2006/05/30 · openalex publication_date 2006/09/18 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
We present high angular resolution (~1'' and 0 6) millimeter interferometric observations of the 12 CO(1-0) and 12 CO(2-1) line emission in the central 300 pc of the late-type spiral galaxy NGC 6946. The data, obtained with the IRAM Plateau de Bure Interferometer (PdBI), allow the first detection of a molecular gas spiral in the inner ~10'' (270 pc) with a large concentration of molecular gas ( M ~ 1.6 × 10 7 M ☉ ) within the inner 60 pc. This nuclear clump shows evidence for a ringlike geometry with a radius of ~10 pc as inferred from the position-velocity diagrams. Both the distribution of the molecular gas and its kinematics can be well explained by the influence of an inner stellar bar of about 400 pc 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, NGC 6946 is a prime example of molecular gas kinematics being driven by a small-scale, secondary stellar bar.