Determination of supermassive black hole spins in local active galactic nuclei

We estimated the radiative efficiency and spin value for a number of local active galactic nuclei (AGNs) with z<0.34 using three popular models connecting the radiative efficiency with such parameters of AGNs as mass of supermassive black hole (SMBH), angle between the line of sight and the axis of the accretion disk and bolometric luminosity. Analysis of the obtained data shows that the spin value decreases with cosmic time, which is in agreement with results of theoretical calculations for low-redshift AGNs of other authors. Also, we found that the spin value increases with the increasing mass of SMBH and bolometric luminosity. This is the expected result that corresponds to theoretical calculations. Analysis of the distribution of the spin values shows a pronounced peak in the distribution in 0.75<a<1.0 range. similar to 40% of objects have spin a>0.75 and similar to 50% of objects have spin a>0.5. These results are in good agreement with our previous results and with the results of other authors.