The warm molecular hydrogen of PKS B1718-649: feeding a newly born radio
  AGN
  We present new SINFONI VLT observations of molecular hydrogen (H2) in the
central regions (< 2.5 kpc) of the youngest and closest radio source PKS
B1718-649. We study the distribution of the H2 traced by the 1-0 S(1)
ro-vibrational line, revealing a double disk structure with the kinematics of
both disks characterised by rotation. An outer disk (r > 650 pc) is aligned
with other components of the galaxy (atomic hydrogen, stars, dust), while the
inner disk (r< 600 pc) is perpendicular to it and is polar with respect to the
stellar distribution. However, in the innermost 75 pc, the data show the
presence of H2 gas redshifted with respect to the rotating inner disk ($\Delta
v\,$+150 km/s) which may trace gas falling into the super-massive black hole
associated with the central radio source. Along the same line of sight, earlier
observations had shown the presence in the central regions of PKS B1718-649 of
clouds of atomic hydrogen with similar unsettled kinematics. The range of
velocities and mass of these unsettled clouds of HI and H2 suggest they may be
actively contributing in fuelling the central newly-born radio source.
