Polarization Of Quasars: Electron And Resonant Line Scattering In The Broad Absorption Line Region

About 10-20 % optically selected QSOs exhibit broad absorption troughs in resonant lines up to 0.1c blue-ward of the corresponding emission lines. Usually the Broad Absorption Lines (BAL) are detected only in high ionization ones, such as CIV, NV, SiIV and OVI, named high ionized BAL, but 10% of BAL QSOs show also low ionization lines, such as MgII, AlIII and even FeII. The blue shift of the absorption lines suggests that they are formed in a partially ionized wind, outflowing from the quasar. It is widely accepted that the broad absorption line region (BALR) exists in most (if not all) quasars with a small covering factor. Recent works showed that the BALR is optically thick to soft and even medium energy X-rays, with a typical hydrogen column density of a few 1023 to > 1024 cm"2, and to major resonant absorption lines, with optical depth between 20 and 80. The electron scattering and resonant line scattering in the thick absorber might contribute significantly to the polarization of the continuum and/or broad absorption lines of quasars. Observations support that the BAL QSOs are the only high-polarization population among the radio-quiet QSOs. There are many polarization observations, e.g. polarization of the BALRs(?)that of the continuum(?)that of the broad emission lines(BELs) and polarization position angle is rotating across the BALs and so on. These provides rich information to study the structure and kinematics of BALR in QSOs. Our study of polarization of quasars during my phd is introduced in this thesis.In this thesis, we present a detailed study of the electron scattering in the BALR by assuming an equatorial and axisymmetric outflow model. Monte-Carlo...