SIMBAD references

In this Letter, under the widely accepted theoretical accretion disc model for the double-peaked emitter 3C 390.3, the extended disc-like broad-line region can be well split into 10 rings, and then the time lags between the lines from the rings and the continuum emission are estimated, based on the observed spectra around 1995. We can find one very strong correlation between the determined time lags (in units of light-day) and the flux-weighted radii (in units of RG) of the rings, which is well consistent with the expected results through the theoretical accretion disc model. Moreover, through the strong correlation, the black hole masses of 3C 390.3 are independently estimated as ∼ 109M☉, the same as the reported black hole masses in the literature. The consistencies provide further evidence to strongly support the accretion disc origination of the double-peaked broad Balmer lines of 3C 390.3.