  We present the results of a new set of hydrodynamical simulations of hot gas
flows in model elliptical galaxies with the following characteristics: the
spatial luminosity distribution approaches a power law form at small radii, in
accordance with the results of recent ground based observations, and with the
Hubble Space Telescope; the dark matter has a peaked profile too, as indicated
by high resolution numerical simulations of dissipationless collapse; the dark
to luminous mass ratio spans a large range of values, including low values
found by optical studies confined to within two effective radii; finally, the
type Ia supernova rate is that given by the latest estimates of optical
surveys, or zero, as suggested by the iron abundances recently measured in the
hot gas. We find that the resulting gas flows are strongly decoupled: an inflow
develops in the central region of the galaxies, while the external parts are
still degassing, i.e., the flows are mostly partial winds. This behavior can be
explained in terms of the local energy balance of the hot gas. A large spread
in the X-ray luminosity Lx at fixed optical luminosity Lb can be produced as in
previous simulations that used King models plus massive quasi-isothermal dark
halos, and higher supernova rates; the key factor causing large Lx variations
is now the size of the central inflow region. The highest Lx observed
correspond to global inflows. Finally, non negligible amounts of cold gas can
be produced by the partial winds; this could be an explanation for the possible
discovery of cold matter at the center of elliptical galaxies, an alternative
to the presence of a steady state cooling flow.
