AGN wind scaling relations and the co-evolution of black holes and
  galaxies
  Feedback from accreting SMBHs is often identified as the main mechanism
responsible for regulating star-formation in AGN host galaxies. However, the
relationships between AGN activity, radiation, winds, and star-formation are
complex and still far from being understood. We study scaling relations between
AGN properties, host galaxy properties and AGN winds. We then evaluate the wind
mean impact on the global star-formation history, taking into account the short
AGN duty cycle with respect to that of star-formation. We first collect AGN
wind observations for 94 AGN with detected massive winds at sub-pc to kpc
spatial scales. We then fold AGN wind scaling relations with AGN luminosity
functions, to evaluate the average AGN wind mass-loading factor as a function
of cosmic time. We find strong correlations between the AGN molecular and
ionised wind mass outflow rates and the AGN bolometric luminosity. The power
law scaling is steeper for ionised winds (slope 1.29+/-0.38) than for molecular
winds (0.76+/-0.06), meaning that the two rates converge at high bolometric
luminosities. The molecular gas depletion timescale and the molecular gas
fraction of galaxies hosting powerful AGN winds are 3-10 times shorter and
smaller than those of main-sequence galaxies with similar SFR, stellar mass and
redshift. These findings suggest that, at high AGN bolometric luminosity, the
reduced molecular gas fraction may be due to the destruction of molecules by
the wind, leading to a larger fraction of gas in the atomic ionised phase. The
AGN wind mass-loading factor $\eta=\dot M_{OF}/SFR$ is systematically higher
than that of starburst driven winds. Our analysis shows that AGN winds are, on
average, powerful enough to clean galaxies from their molecular gas only in
massive systems at z<=2, i.e. a strong form of co-evolution between SMBHs and
galaxies appears to break down for the least massive galaxies.
