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 \sim 100 - 1000 km { s } ^ { -1 } , and on comparable but less stringent grounds the ultra-fast outflows ( UFOs ) , v \sim 0.03 - 0.3 c .
If comparable with the escape velocity of the system ; the first is naturally located at distances of the dusty torus , \approx 1 pc , and the second at sub-parsec scales , \approx 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 .