AGN feedback though the cosmic times

Why do black holes in galactic nuclei have masses proportional to
bulge masses and luminosities? Why did galaxies at a certain point of
their cosmological evolution, stop to form stars? What is the path(s)
and the mechanism(s) leading the transition from gas rich,
star-forming galaxies, to red passive galaxies, deprived of all their
gas? Theory and few observations suggest that AGN driven super winds
(=feedback) play a major role in all these transformations. The two
main building blocks of this scenario are: 1) AGN outflows, which
inject energy in their environment; 2) the interaction of these flows
with the galaxy interstellar matter, and its
physical/chemical/geometrical modification.

I will first review AGN outflows seen in different gas phases and at
different scales.  I will then present searches for "direct" evidence
of AGN feedback in bright nearby AGN, linking accretion and ejection
occurring on sub-parsec scale in galaxy nuclei to the transformations
occurring in the rest of the galaxy. I will finally discuss the
perspectives of extending these studies up to z=1-3, the golden epoch
of AGN and galaxy activity.