  Large scale X-ray jets that extend to >100 kpc distances from the host galaxy
indicate the importance of jets interactions with the environment on many
different physical scales. Morphology of X-ray clusters indicate that the
radio-jet activity of a cD galaxy is intermittent. This intermittency might be
a result of a feedback and/or interactions between galaxies within the cluster.
Here we consider the radiation pressure instability operating on short
timescales (<10^5 years) as the origin of the intermittent behaviour. We test
whether this instability can be responsible for short ages (< 10^4 years) of
Compact Symmetric Objects measured by hot spots propagation velocities in VLBI
observations. We model the accretion disk evolution and constrain model
parameters that may explain the observed compact radio structures and
over-abundance of GPS sources. We also describe effects of consequent
outbursts.
