The Broad Emission-Line Profiles and Profile Variability of the Seyfert 1 Galaxy Arakelian 120

Abstract

We present Hα and Hβ broad emission-line profiles of the Seyfert galaxy Arakelian 120 from the past ~10 yr, representing over 100 spectroscopic observations. The broad emission-line profiles of the Balmer lines are complex in structure and variable; the profile variations themselves are complex. We attempt to isolate separate emitting components within the profiles through profile differencing and profile fitting. If Gaussian-like, at least four separate components are present in the broad Balmer emission lines. The broad emission-line profiles of other emission lines (optical and UV) are also presented, and evidence is given for a stratified BLR. Using the results of Joly, we demonstrate that the Fe II multiplets 25 and 36 (in addition to m42) may be present in the Hβ profile and in its "red shelf."