  Photon trapping and outflow are two key physics associated with the
supercritical accretion flow. We investigate the conflict between these two
processes based on two-dimensional radiation-hydrodynamic (RHD) simulation data
and construct a simplified (radially) one-dimensional model. Mass loss due to
outflow, which is not considered in the slim-disk model, will reduce surface
density of the flow, and if very significant, it will totally suppress photon
trapping effects. If the photon trapping is very significant, conversely,
outflow will be suppressed because radiation pressure force will be reduced. To
see what actually occurs, we examine the RHD simulation data and evaluate the
accretion rate and outflow rate as functions of radius. We find that the former
monotonically decreases, while the latter increases, as the radius decreases.
However, the former is kept constant at small radii, inside several
Schwarzschild radii, since the outflow is suppressed by the photon trapping
effects. To understand the conflict between the photon trapping and outflow in
a simpler way, we model the radial distribution of the accretion rate from the
simulation data and build up a new (radially) one-dimensional model, which is
similar to the slim-disk model but incorporates the mass loss effects due to
the outflow. We find that the surface density (and, hence, the optical depth)
is much reduced even inside the trapping radius, compared with the case without
outflow, whereas the effective temperature distribution hardly changes. That
is, the emergent spectra do not sensitively depend on the amount of mass
outflow. We conclude that the slim-disk approach is valid for interpreting
observations, even if the outflow is taken into account.
