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We report the discovery of a 3 kpc disk of few 10^9 Ms of dense, warm H_2 in the nearby radio galaxy 3C326 N, which shows no signs of on-going or recent star formation and falls a factor 60 below the Schmidt-Kennicutt law. VLT/SINFONI imaging spectroscopy shows broad (FWHM sim 500 km/s) ro-vibrational H_2 lines across all of the disk, with irregular profiles and line ratios consistent with shocks. The ratio of turbulent and gravitational energy suggests that the gas is highly turbulent and not gravitationally bound. In absence of the driving by the jet, short turbulent dissipation times suggest the gas should collapse rapidly and form stars, at odds with the recent star-formation history. Motivated by hydrodynamic models of rapid H_2 formation boosted by turbulent compression, we propose that the molecules formed from diffuse atomic gas in the turbulent jet cocoon. Since the gas is not self-gravitating, it cannot form molecular clouds or stars while the jet is active, and is likely to disperse and become atomic again after the nuclear activity ceases. We speculate that very low star-formation rates are to be expected under such conditions, provided that the large-scale turbulence sets the gas dynamics in molecular clouds. Our results illustrate that jets may create large molecular reservoirs as expected in positive feedback scenarios of AGN-triggered star formation, but that this alone is not sufficient to trigger star formation.
An imaging survey of CO(1-0), HCN(1-0), and HCO$^+$(1-0) lines in the centers of nearby Seyfert galaxies has been conducted using the Nobeyama Millimeter Array and the RAINBOW interferometer. Preliminary results reveal that 3 Seyferts out of 7 show a
We present ALMA Cycle-0 observations of the CO (6-5) line emission and of the 435um dust continuum emission in the central kpc of NGC 1614, a local luminous infrared galaxy (LIRG) at a distance of 67.8 Mpc (1 arcsec = 329 pc). The CO emission is well
By combining two surveys covering a large fraction of the molecular material in the Galactic disk we investigate the role the spiral arms play in the star formation process. We have matched clumps identified by ATLASGAL with their parental GMCs as id
It remains unclear what sets the efficiency with which molecular gas transforms into stars. Here we present a new VLA map of the spiral galaxy M51 in 33GHz radio continuum, an extinction-free tracer of star formation, at 3 scales (~100pc). We combine
We present a 190-307 GHz broadband spectrum obtained with Z-Spec of NGC 1068 with new measurements of molecular rotational transitions. After combining our measurements with those previously published and considering the specific geometry of this Sey