AGN, the virialization assumption has been widely and commonly accepted. Here, we should find that the assumption is also valid for the double-peaked emitter 3C390.3.

As we have shown above, the proposed accretion disk model should be appropriate for the double-peaked emitter 3C390.3. Considering the oversimplified case, the disk-like BLR of 3C390.3 is separated into one inner region with radius from $R_{in}$ to $0.5\times (R_{in} + R_{out})$ and the other outer region, then the flux weighted distance between the two regions to the central black hole can be calculated based on the simple elliptical accretion disk model (Eracleous et al. 1995) $R_{BLR,1}\sim445{\rm R_G}$ for the inner part of the BLR and $R_{BLR,2}\sim987{\rm R_G}$ for the outer part of the BLR. According to the results shown in Zhang (2011b), the size of total BLR ($R_{BLR}$) can be written as $$R_{BLR} = R \times R_{BLR,1} + (1-R)\times R_{BLR,2}$$ Based on the values of R listed in Table 1 and the values of $R_{BLR,1}$ and $R_{BLR,2}$, we will have the size of BLR $R_{BLR}$ varying from $\sim596{\rm R_G}$ to $\sim715{\rm R_G}$. Moreover, based on the Virialization assumption, $R_{BLR}\times\sigma^2 = constant$ (or $(\frac{\sigma_{max}}{\sigma_{min}})^2=\frac{R_{BLR,max}}{R_{BLR,min}}$), combining with the measured line width in Table 1, the expected 