The Impact Of Radio-jet Driven Outflows On The Molecular Gas In Powerful Radio-galaxies

Observations of ionized and neutral gas outflows in radio-galaxies (RG) suggest that AGN feedback has a galaxy-scale impact on the host ISM, but it is still unclear how the molecular gas is affected. Thus it is crucial to determine the physical conditions of the molecular gas in powerful RG to understand how radio sources may regulate the star formation in their host galaxies. We present deep Spitzer IRS high-resolution spectroscopy of 8 nearby RG that show fast HI outflows. Strikingly, all of these RG have extremely bright H2 mid-IR lines that cannot be accounted for by UV or X-ray heating. This strongly suggests that the radio jet, which drives the HI outflow, is also responsible for the shock-excitation of the warm H2 gas. In addition, the warm H2 gas does not share the kinematics of the ionized/neutral gas. In most of the sources, the mid-IR H2 lines are unresolved by the IRS, whereas ionized gas lines (e.g. NeII, NeIII) have FWHM up to 1200 km/s. If the dissipation of a small fraction (