2026ApJ..1000..180W

We present the results of broad-line region (BLR) dynamical modeling for eight high-mass active galactic nuclei (AGNs) from the Seoul National University AGN Monitoring Project, by constraining BLR geometry and kinematics as well as black hole (BH) mass (M_BH). We find that the Hβ-emitting BLRs are best described as thick disks viewed at intermediate inclinations, with emission preferentially originating from the far side of the BLR. BLR kinematics show a combination of rotational, inflowing, and outflowing components. By comparing the M_BH from dynamical modeling with the virial products based on reverberation lags and line widths, we determine the virial factor f for individual AGNs. Combining our sample with those M_BH consistently determined via BLR dynamical modeling, yielding a total of 38 objects, we derive a virial factor for future M_BH estimation of log₁₀(f)_pred = 0.69 ± 0.21 based on σ_line,rms and -0.08 ± 0.23 based on FWHM_mean. The derived virial factor is consistent with that inferred by aligning the reverberation-mapped AGNs with quiescent galaxies in the M_BH-σ_* relation, supporting the assumption that local active and inactive galaxies follow the same M_BH-σ_*relation. Our updated f values exhibit an intrinsic dispersion of ∼0.2 dex, which allows for more precise M_BH estimates than those based on the M_BH-σ_* relation. Our sample extends the reverberation sample with BLR dynamic modeling to the M_BH ∼ [10⁸, 10^8.5]M_⊙, where the virial factor from the AGN M_BH-σ_* relation remains poorly constrained, underscoring the unique value of dynamical modeling analysis in constraining the M_BH of the most massive BHs.