The observations of blue-shifted absorption lines by metals suggest the outflow in the
active galactic nuclei (AGNs). Especially, the outflow with the large velocity,
10,000-90,000 km/s (0.3c), suggested by the highly ionized iron lines, are called
Ultra Fast Outflows (UFOs). The origin of the outflow is still unknown and the existing
phenomenological model for AGNs cannot reproduce these outflows. 

Our aims are to investigate the dynamics and structure of the outflow, and to explain
the origin of the absorption lines. We focus on the plausible model for the outflows, the
line-driven disk wind model, in which the radiation force due to spectral lines (line
force) accelerates the matter on the surface of the accretion disk and induces the disk
wind.

We performed the two-dimensional radiation hydrodynamic simulations of line-driven disk
wind. We found that the funnel-shaped disk wind is successfully launched from the
accretion disk surface and that the UFO features (ionization degree, velocity, and
column density) are reproduced. The time-averaged UFO detection rate is 20–30%, which is
comparable to or slightly smaller than that estimated by observations. Also, we mention
the time variability, the black hole mass dependence, and the Eddington ratio
dependence.