Star formation and gas flows in the centre of the NUGA galaxy NGC 1808
  observed with SINFONI
  NGC 1808 is a nearby barred spiral galaxy which hosts young stellar clusters
in a patchy circumnuclear ring with a radius of $\sim 240\,\mathrm{pc}$. In
order to study the gaseous and stellar kinematics and the star formation
properties of the clusters, we perform seeing-limited $H+K$-band near-infrared
integral-field spectroscopy with SINFONI of the inner $\sim 600\,\mathrm{pc}$.
From the $M_\mathrm{BH}-\sigma_*$ relation, we find a black hole mass of a few
$10^7\,M_\odot$. We estimate the age of the young stellar clusters in the
circumnuclear ring to be $\lesssim 10\,\mathrm{Myr}$. No age gradient along the
ring is visible. However, the starburst age is comparable to the travel time
along the ring, indicating that the clusters almost completed a full orbit
along the ring during their life time. In the central $\sim 600\,\mathrm{pc}$,
we find a hot molecular gas mass of $\sim 730\,M_\odot$ which, with standard
conversion factors, corresponds to a large cold molecular gas reservoir of
several $10^8\,M_\odot$, in accordance with CO measurements from the
literature. The gaseous and stellar kinematics show several deviations from
pure disc motion, including a circumnuclear disc and signs of a nuclear bar
potential. In addition, we confirm streaming motions on $\sim 200\,\mathrm{pc}$
scale that have recently been detected in CO(1-0) emission. Due to our enhanced
angular resolution of $<1\,\mathrm{arcsec}$, we find further streaming motion
within the inner arcsecond, that have not been detected until now. Despite the
flow of gas towards the centre, no signs for significant AGN activity are
found. This raises the questions what determines whether the infalling gas will
fuel an AGN or star formation.
