2025/04/07 by XueGuang, Zhang
#Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences
paper · doi:10.48550/arxiv.2504.05531
Broad emission line regions (BLRs) lying into central accretion disks has been widely accepted to explain the unique double-peaked broad emission lines in Active Galactic Nuclei (double-peaked BLAGNs). Here, accepted the accretion disk origin, periodic variations of central wavelength λ0 (the first moment) and line width σ (the second moment) of double-peaked broad emission lines are theoretically simulated and determined. Furthermore, through theoretically simulated periodicities of Tλ0 and Tσ for variations of λ0 and σ, periodicity ratio Rfs of Tλ0 to Tσ to be around 2 can be applied to support the spiral arms to be more preferred in BLRs lying into central accretion disks. Then, periodic variations of λ0 and σ are determined and shown in the known double-peaked BLAGN NGC1097, leading to the parameter Rfs∼2, which can be applied as clues to support that the structure of spiral arms in disk-like BLRs in central accretion disk should be the most compelling interpretation to the variability of double-peaked broad Hα in NGC1097. The results provide clean criteria to test accretion disk origins of double-peaked broad emission lines in AGN.