The fast molecular outflow in the Seyfert galaxy IC5063 as seen by ALMA
  We use high-resolution (0.5 arcsec) CO(2-1) observations performed with ALMA
to trace the kinematics of the molecular gas in the Seyfert 2 galaxy IC5063. A
fast outflow of molecular gas extends along the entire radio jet, with the
highest outflow velocities about 0.5kpc from the nucleus, at the location of
the brighter hot-spot in the W lobe. The data show that a massive, fast outflow
with velocities up to 650 km/s of cold molecular gas is present, in addition to
one detected earlier in warm H2, HI and ionised gas. Both the central AGN and
the radio jet could energetically drive the outflow. However, the
characteristics of the outflowing gas point to the radio jet being the main
driver. This is important, because IC5063, although one of the most powerful
Seyfert galaxies, is a relatively weak radio source (P = 3x10^23 W/Hz). All the
observed characteristics can be described by a scenario of a radio plasma jet
expanding into a clumpy medium, interacting directly with the clouds and
inflating a cocoon that drives a lateral outflow into the interstellar medium.
This model is consistent with results obtained by recent simulations such as
those of Wagner et al.. A stronger, direct interaction between the jet and a
gas cloud is present at the location of the brighter W lobe. Even assuming the
most conservative values for the conversion factor CO-to-H2, the mass of the
outflowing gas is between 1.9 and 4.8x10^7 Msun. These amounts are much larger
than those of the outflow of warm gas (molecular and ionized) and somewhat
larger than of the HI outflow. This suggests that most of the observed cold
molecular outflow is due to fast cooling after being shocked. This gas is the
end product of the cooling process. Our CO observations demonstrate that fast
outflows of molecular gas can be driven by relativistic jets.
