Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-09-17
Astronomy and Astrophysics
Astrophysics
54 pages, 26 figures, accepted by ApJS, contact author by email for version with higher resolution figures
Scientific paper
10.1086/509602
Recent works showed that the absorbing material in broad absorption line (BAL) quasars is optically thick to major resonant absorption lines. This material may contribute significantly to the polarization in the absorption lines. In this paper, we present a detailed study of the resonant line scattering process using Monte-Carlo method to constrain the optical depth, the geometry and the kinematics of BAL Region (BALR). By comparing our results with observed polarized spectra of BAL quasars, we find: (1) Resonant scattering can produce polarization up to 9% at the absorption trough for doublet transitions and up to 20% for singlet transitions in radially accelerated flows. To explain the large polarization degree in the CIV, NV absorption line troughs detected in a small fraction of BAL QSOs, a nonmonotonic velocity distribution along the line of sight or/and additional contribution from the electron scattering region is required. (2) The rotation of the flow can lead to the rotation of the polarization position angle (PA) in the line trough. Large extending angle of BALR is required to produce the observed large PA rotation in a few BAL QSOs. (3) A large extending angle of BALR is required to explain a sub-trough in the polarized flux that was observed in a number of BAL QSOs. (4) The resonant-scattering can contribute a significant part of NV emission line in some QSOs, and may give rise to anomalous strong NV lines in these quasars. (5) The polarized flux and PA rotation produced by the resonant scattering in non-BAL is uniquely asymmetric, which may be used to test the presence of BALR in non-BAL QSOs.
Wang Hui-Yuan
Wang Jun-Xian
Wang Ting-Gui
No associations
LandOfFree
Polarization of Quasars: Resonant Line Scattering in the Broad Absorption Line Region does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Polarization of Quasars: Resonant Line Scattering in the Broad Absorption Line Region, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Polarization of Quasars: Resonant Line Scattering in the Broad Absorption Line Region will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-704405