Fast outflows in broad absorption line quasars and their connection with
  CSS/GPS sources
  Broad absorption line quasars are among the objects presenting the fastest
outflows. The launching mechanism itself is not completely understood. Models
in which they could be launched from the accretion disk, and then curved and
accelerated by the effect of the radiation pressure, have been presented. We
conducted an extensive observational campaign, from radio to optical band, to
collect information about their nature and test the models present in the
literature, the main dichotomy being between a young scenario and an
orientation one. We found a variety of possible orientations, morphologies, and
radio ages, not converging to a particular explanation for the BAL phenomenon.
From our latest observations in the m- and mm-band, we obtained an indication
of a lower dust abundance with respect to normal quasars, thus suggesting a
possible feedback process on the host galaxy. Also, in the low-frequency regime
we confirmed the presence of CSS components, sometime in conjunction with a GPS
one already detected at higher frequencies. Following this, about 70% of our
sample turns out to be in a GPS or CSS+GPS phase. We conclude that fast
outflows, responsible for the BAL features, can be more easily present among
objects going through a restarting or just-started radio phase, where radiation
pressure can substantially contribute to their acceleration.
