Radio Jets Clearing the Way Through a Galaxy: Watching Feedback in
  Action
  The energy released by an active galactic nucleus (AGN) has a strong impact
on the surrounding interstellar medium (ISM). This feedback is considered to be
the regulating factor for the growth of the central massive black hole, and for
the rate of star formation in a galaxy. We have located, using Very Long
Baseline Interferometry (VLBI), the fast outflow of neutral hydrogen in the
young, restarted radio loud AGN 4C12.50. The outflow is located 100 pc from the
nucleus where the radio jet interacts with the ISM, as well as around the
associated radio lobe. These observations show that the radio plasma drives the
outflow and removes gas from the central regions, and that jet driven outflows
can play a relevant role in feedback mechanisms.
