2005PASJ...57..183X

begin{HTML} The black hole mass, along with the ratio of the accretion rate to the Eddington accretion rate, is a fundamental parameter of active galactic nuclei. Using our new method to estimate the black hole mass, we developed our sample and estimated black hole masses, indicated by <i>M</i> _H for 12 blazars. We compared 12 cases, for each of which the relevant black hole mass was also estimated by the <i>L</i>₅₁₀₀-<i>R</i>_BLR relation or the <i>M</i> _BH-s correlation method, which is indicated by <i>M</i>_s. We also found that (1) <i>M</i>_H values are systematically lower than <i>M</i>_s, but the differences between <i>M</i>_s and <i>M</i>_H are very small for most sources; (2) there is a significant correlation between <i>M</i>_s and <i>M</i>_H, the correlation coefficient being <i>r</i> = 0.66 with a chance probability of <i>p</i> ∼ 1.9 x 10^-2. Based on these properties mentioned above, we have shown that the small systematical difference between <i>M</i>_s and <i>M</i>_H is probably due to some systematic errors in our method.