Modeling line-driven disk wind for broad absorption lines of quasars
  The disk wind, which is powered by the radiation force due to spectral lines
(line force), is studied for broad absorption line (BAL) quasars. We
investigate the structure of the disk wind based on the non-hydrodynamic method
and compare with wind properties inferred from X-ray observations of BAL
quasars. In this paper, we apply the stellar wind theory to the initial
condition (the mass outflow rate at the base of the wind). We found the
funnel-shaped winds with a half opening angle of 50^{circ} for the case of
epsilon=0.3-0.9 and M_{BH}=10^{7-8.5}M_odot, where epsilon is the Eddington
ratio and M_{BH} is the black hole mass. Thus, the absorption features are
observed for an observer of which a viewing angle is around 50^{circ}. A
probability of BAL quasars is 7-11%, which is roughly consistent the abundance
ratio of BAL quasars, 10-15%. Here, the probability is estimated by the solid
angle, that the absorbing features would be detected, divided by 4pi. In
contrast, if the Eddington ratio is smaller than 0.01 or if the black hole is
very massive, M_{BH} < 10^9M_{odot}, the disk wind is not launched due to the
less effective line force. Then, the quasars are identified as non-BAL quasars
independently of the observer's viewing angle.
