  X-ray and UV line emission in X-ray binaries can be accounted for by a hot
corona. Such a corona forms through irradiation of the outer disk by radiation
produced in the inner accretion flow. The same irradiation can produce a strong
outflow from the disk at sufficiently large radii. Outflowing gas has been
recently detected in several X-ray binaries via blue-shifted absorption lines.
However, the causal connection between winds produced by irradiation and the
blue-shifted absorption lines is problematic, particularly in the case of GRO
J1655-40. Observations of this source imply wind densities about two orders of
magnitude higher than theoretically predicted. This discrepancy does not mean
that these `thermal disk-winds' cannot explain blue-shifted absorption in other
systems, nor that they are unimportant as a sink of matter. Motivated by the
inevitability of thermal disk-winds and wealth of data taken with current
observatories such as Chandra, XMM-Newton and Suzaku, as well as the future
AstroH mission, we decided to investigate the requirements to produce very
dense winds. Using physical arguments, hydrodynamical simulations and
absorption line calculations, we found that modification of the heating and
cooling rates by a factor of a few results in an increase of the wind density
of up to an order of magnitude and the wind velocity by a factor of about two.
Therefore, the mass loss rate from the disk can be one, if not even two orders
of magnitude higher than the accretion rate onto the central object. Such a
high mass loss rate is expected to destabilize the disk and perhaps provides a
mechanism for state change.
