M. Dekool et Mc. Begelman, RADIATION PRESSURE-DRIVEN MAGNETIC DISK WINDS IN BROAD ABSORPTION-LINE QUASI-STELLAR OBJECTS, The Astrophysical journal, 455(2), 1995, pp. 448-455
We explore a model in which QSO broad absorption Lines (BALs) are form
ed in a radiation pressure-driven wind emerging from a magnetized accr
etion disk. The magnetic field threading the disk material is dragged
by the flow and is compressed by the radiation pressure until it is dy
namically important and strong enough to contribute to the confinement
of the BAL clouds. We construct a simple self-similar model for such
radiatively driven magnetized disk winds, in order to explore their pr
operties. It is found that solutions exist for which the entire magnet
ized flow is confined to a thin wedge over the surface of the disk. Fo
r reasonable values of the mass-loss rate, a typical magnetic field st
rength such that the magnetic pressure is comparable to the inferred g
as pressure in BAL clouds, and a moderate amount of internal soft X-ra
y absorption, we find that the opening angle of the how is approximate
ly 0.1 rad, in good agreement with the observed covering factor of the
broad absorption line region.