Cold gas dynamics in Hydra-A: evidence for a rotating disk
  We present multi-frequency observations of the radio galaxy Hydra-A (3C218)
located in the core of a massive, X-ray luminous galaxy cluster. IFU
spectroscopy is used to trace the kinematics of the ionised and warm molecular
hydrogen which are consistent with a ~ 5 kpc rotating disc. Broad,
double-peaked lines of CO(2-1), [CII]157 $\mu$m and [OI]63 $\mu$m are detected.
We estimate the mass of the cold gas within the disc to be M$_{gas}$ = 2.3
$\pm$ 0.3 x 10$^9$ M$_{\odot}$. These observations demonstrate that the complex
line profiles found in the cold atomic and molecular gas are related to the
rotating disc or ring of gas. Finally, an HST image of the galaxy shows that
this gas disc contains a substantial mass of dust. The large gas mass, SFR and
kinematics are consistent with the levels of gas cooling from the ICM. We
conclude that the cold gas originates from the continual quiescent accumulation
of cooled ICM gas. The rotation is in a plane perpendicular to the projected
orientation of the radio jets and ICM cavities hinting at a possible connection
between the kpc-scale cooling gas and the accretion of material onto the black
hole. We discuss the implications of these observations for models of cold
accretion, AGN feedback and cooling flows.
