The Shape of the Fe Kα Spectral Line in the Case of Partly Obscured Accretion Disk

Abstract

X‐ray emission from a relativistic accretion disk around central Black Hole (BH) of Active Galactic Nuclei (AGN) could be significantly absorbed by an outfiowing wind, especially in case of so‐called Low Ionization Broad Absorption Line (LoBAL) quasars. Recent observations of such quasars (e.g. Mrk 231) confirmed the presence of X‐ray absorbers in these objects. In this paper we studied the changes of the Fe Kα spectral line shape in the case when a portion of the accretion disk is blocked from our view by the X‐ray absorbing/obscuring material, while the rest of the accretion disk is less absorbed/obscured and visible. To analyze the disk emission we used a ray‐tracing method considering both metrics: Schwarzschild and Kerr. Obtained results show that absorbing/obscuring material can induce significant changes in the Fe Kα line shape, depending on geometry of the X‐ray absorbers.