2016A&A...588A..46M

We present new SINFONI VLT observations of molecular hydrogen (H₂) in the central regions (<2.5kpc) 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>650pc) is aligned with other components of the galaxy (atomic hydrogen, stars, dust), while the inner disk (r<600pc) is perpendicular to it and is polar with respect to the stellar distribution. However, in the innermost 75pc, the data show the presence of H₂ gas redshifted with respect to the rotating inner disk (δv~+150km/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 H i and H₂ suggest they may be actively contributing to fuelling the central newly born radio source.