Modelling the Spectra of Quasars: Clumpy Winds and X-ray Properties
Abstract
Broad, blue shifted absorption lines in the ultraviolet (UV) are seen in approximately 20% of quasi-stellar objects (QSOs), providing clear evidence that mass-loaded outflows are present in such systems (known as BALQSOs). These outflows may take the form of winds emanating from the accretion disk, which offer potential for a feedback mechanism with the host galaxy. Disk winds are also important in unification scenarios for QSOs and active galactic nuclei (AGN). We present Monte Carlo radiative transfer simulations using a simple biconical disk wind model which has already successfully reproduced BAL profiles. Previous models exhibited a well-documented `over-ionization' problem- it is difficult to maintain an ionization state which produces significant line opacity in UV resonance species such as CIV, while remaining consistent with observed X-ray luminosities of QSOs. We attempt to address this problem by examining the effect of clumping and different mass-loss prescriptions on the ionization state and inferred X-ray properties. We also investigate the important emergent observable quantities as a function of viewing angle. We make comparisons to population studies of QSOs and AGN, and discuss our results with reference to ultra-fast outflows in AGN and potential super-Eddington accretion in ultra luminous X-ray sources (ULXs).
- Publication:
-
The Extremes of Black Hole Accretion
- Pub Date:
- July 2015
- Bibcode:
- 2015ebha.confE..47M