UltraFast Outflows ( UFOs ) , seen as X-ray blueshifted absorption lines in active galactic nuclei ( AGNs ) , are considered to be a key mechanism for AGN feedback .
In this scenario , UFO kinetic energy is transferred into the cold and extended molecular outflow observed at the mm/sub-mm wavelength , which blows away the gas and suppresses star formation and accretion onto the central black hole ( BH ) .
However , the energy transfer between the inner UFO and the outer molecular outflow has not yet fully studied mainly due to the limited sample .
In this paper , we performed comparison of their kinetic energy using the mm/sub-mm published data and the X-ray archival data .
Among fourteen Seyfert galaxies whose molecular outflows are detected in the IRAM/PdBI data , eight targets are bright enough to perform spectral fitting in X-ray , and we have detected UFO absorption lines in six targets with 90 % significance level , using XMM-Newton and Suzaku satellites .
The time-averaged UFO kinetic energy was derived from the spectral fitting .
As a result , we have found that the energy-transfer rate ( kinetic energy ratio of the molecular outflow to the UFO ) ranges from \sim 7 \times 10 ^ { -3 } to \sim 1 , and has a negative correlation with the BH mass , which shows that the AGN feedback is more efficient in the lower mass BHs .
This tendency is consistent with the theoretical prediction that the cooling time scale of the outflowing gas becomes longer than the flow time scale when the BH mass is smaller .