Notes. General properties of the sources considered. (1) – Name of the megamaser galaxy. (2) – Geometric distance in Mpc. (3) – Inclination angle of the maser disk at its innermost radius, rounded to the nearest integer. (4) – Reference for the geometric distance and for the inclination angle: (a) – Impellizzeri et al. (2012); (b) – Humphreys et al. (2013); (c) – Gao et al. (2016); (d) – Kuo et al. (2013); (e) – Kuo et al. (2015); (f) – Reid et al. (2013). (5) – Logarithm of the black hole mass in solar masses. (6)–(7) – Inner and outer masing radii, respectively, in pc. (8) – Radius of the sphere of influence of the BH, computed as R_infl = GM/σ². The velocity dispersions σ are from Greene et al. (2016). All maser disks considered here are well within the sphere of influence of the BH, which dominates the gravitational potential. (9) – Logarithm of the BH accretion rate in solar masses per year. The reference for Cols. 5–7, and 9 is Kuo et al. (2018). (10) – Logarithm of the bolometric luminosity in erg s⁻¹, computed as (see text). (11) – Logarithm of the Eddington ratio, computed as L_bol/L_Edd, where L_Edd = 1.26 × 10³⁸M_•/M_⊙.