On the X-ray low- and high-velocity outflows in AGNs
  An exploration of the relationship between bolometric luminosity and outflow
velocity, for two classes of X-ray outflows in a large sample of active
galactic nuclei has been performed. We find that line radiation pressure could
be one physical mechanism that might accelerate the gas we observe in warm
absorber, v~100-1000 km/s, and on comparable but less stringent grounds the
ultra-fast outflows (UFOs), v~0.03-0.3c. If comparable with the escape velocity
of the system; the first is naturally located at distances of the dusty torus,
~ 1 pc, and the second at sub-parsec scales, ~ 0.01 pc, in accordance with
large set of observational evidence existing in the literature. The
presentation of this relationship might give us key clues for our understanding
of the different physical mechanisms acting in the center of galaxies, the
feedback process and its impact on the evolution of the host galaxy.
