Studying the Complex Absorption and Emission Lines in AGN Spectra

Some spectra of AGN present peculiar line profiles, resulting from dynamical processes such as accretion to and/or ejection of matter from the central source. In this paper we explore the idea that Discrete or Satellite Absorption Compoments (DASs/SACs, respectively) might be responsible for the absorption line peculiarities in at least some AGN. We first summarize the main points of a kinematical model enabling us to study the density regions in the plasma surrounding the central source, where we believe the DACs/SACs phenomena take place. Using this model we study the UV line profiles of eight BAL QSOs, deriving several physical parameters of the regions where these spectral lines originate. Finally, we discuss possible interpretations for the origin of the phenomena that arc responsible for the observed spectral line peculiarities in AGN.