Radio jets: properties, life and impact
  Our view of the properties of extragalactic radio jets and the impact they
have on the host galaxy has expanded in the recent years. This has been
possible thanks to the data from new or upgraded radio telescopes. This review
briefly summarises the current status of the field and describes some of the
exciting recent results and the surprises they have brought. In particular, the
physical properties of radio jets as function of their radio power will be
discussed together with the advance made in understanding the life-cycle of
radio sources. The evolutionary stage (e.g. newly born, dying, restarted) of
the radio AGN can be derived from their morphology and properties of the radio
spectra. The possibilities offered by the new generation of low-frequency radio
telescopes make it possible to derive (at least to first order) the time-scale
spent in each phase. The presence of a cycle of activity ensures a recurrent
impact of the radio jets on their surrounding inter-stellar and inter-galactic
medium and, therefore, their relevance for AGN feedback. The last part is
dedicated to the recent results showing the effect of jets on the surrounding
galactic medium. The predictions made by numerical simulations on the impact of
a radio jet (and in particular a newly born jet) on a clumpy medium describe
well what is seen by the observations. The high resolution studies of
jet-driven outflows of cold gas (HI and molecular) has provided new important
addition both in term of quantifying the impact of the outflows and their
relevance for feedback as well as for providing an unexpected view of the
physical conditions of the gas under these extreme conditions.
