Some Results of Long-Term Spectral Monitoring of NGC 4151, 3C 390.3, and Arp 102B
We present the results of an analysis of the shapes of the profiles of broad lines in three AGNs: NGC 4151, 3C 390.3, and Arp 102B. The common characteristic of the emission line profiles is the presence of a double-peaked component. For NGC 4151 this component is seen only after a detailed profile analysis, while the profile of the broad emission line of Arp 102B consists mainly of the double-peaked component. For each of these and other galaxies we have obtained specific results from the variability of the broad line profiles. The line-continuum correlations in NGC 4151 exhibit complex structure. The dependencies of broad line fluxes on the continuum spit into many short-lived linear dependencies. The transition time between successive dependencies is much shorter than the broad-line region dynamical timescale so they are not caused by redistribution of the line-emitting gas. The line-continuum correlation is far better for the total Hα flux than for any segment of the Hα profile. This cannot be due to observational error. We find that the Balmer line transfer functions for NGC 4151 and 3C 390.3 have a faint long tail, so the BLR can be very spatially extended. In Arp 102B and 3C 390.3 excess emissions relative to the mean profile shift with time from the red to blue wings. No track is seen of the emission shifting from blue to red. We are able to qualitatively model the observed variations of the profile by a model in which anisotropically radiating clouds rotate in predominantly co-planar Keplerian orbits.
AGN Variability from X-Rays to Radio Waves
- Pub Date:
- December 2006