  We present a set of controlled hydrodynamical simulations to study the
effects of strong galactic outflows on the density and temperature structures,
and associated X-ray signatures, of extra-planar and circumgalactic gas. We
consider three initial state models, isothermal, isentropic, and rotating
cooling-flow, for the hot circumgalactic medium (CGM) into which the outflows
are driven. The energy sources are either stellar winds and supernovae, or
active galactic nuclei. We consider energy injection rates in the range
$10^{40} < \dot{E}_{\rm inj} <10^{44.5}$ erg s$^{-1}$, and compute the
time-dependent soft X-ray (0.5-2 keV) surface brightness. For $\dot{E}_{\rm
inj} \gtrsim 10^{41} - 10^{42}$ erg s$^{-1}$, with the exact threshold
depending on the initial CGM state, the X-ray response is dominated by dense
hot gas in the forward shock that eventually fades into the CGM as a sound
wave. The shock surrounds an inner hot bubble leading to a radial flattening of
the X-ray surface brightness. For lower energy injection rates, the X-ray
surface brightness of the initial CGM state is almost unaffected. We present
analytic approximations for the outflow shock propagation and the associated
X-ray emissions.
