We study a sample of 44 low-luminosity radio-loud AGN , which represent a range of nuclear radio-power spanning 5 orders of magnitude , to unveil the accretion mechanism in these galaxies .
We estimate the accretion rate of gas associated with their hot coronae by analyzing archival Chandra data , to derive the deprojected density and temperature profiles in a spherical approximation .
Measuring the jet power from the nuclear radio-luminosity , we find that the accretion power correlates linearly with the jet power , with an efficiency of conversion from rest mass into jet power of \sim 0.012 .
These results strengthen and extend the validity of the results obtained by Allen and collaborators for 9 radio galaxies , indicating that hot gas accretion is the dominant process in FR I radio galaxies across their full range of radio-luminosity .

We find that the different levels of nuclear activity are driven by global differences in the structure of the galactic hot coronae .
A linear relation links the jet power with the host X-ray surface brightness .
This implies that a substantial change in the jet power must be accompanied by a global change in its ISM properties , driven for example by a major merger .
This correlation provides a simple widely applicable method to estimate the jet-power of a given object by observing the intensity of its host X-ray emission .

To maintain the mass flow in the jet , the fraction of gas that crosses the Bondi radius reaching the accretion disk must be \gtrsim 0.002 .
This implies that the radiative efficiency of the disk must be \eta \lesssim 0.005 , an indication that accretion in these objects occurs not only at a lower rate , but also at lower efficiency than in standard accretion disks .