the cool clouds
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In Model 3, we approximate an isothermal equation of state for the cloud, as described above, in order to represent the limit in which cooling is highly efficient. The evolution of the density is shown in Figure \[fig:mod3rho\], while the energies are shown in Figure \[fig:mod3en\]. The isothermal behavior of the cloud leads to nonconservation of the total energy of the cloud plus background, and so we do not plot that here, focusing instead upon the kinetic and internal energies.

As expected, cooling within mixed cells does lead to some cooling of the background gas, as well as some overcooling within the cloud, both of which can be seen in Figure \[fig:mod3en\]. The lack of heating within the cloud leads to additional compression relative to the previous models, reducing its breakup. Overall, however, the transfer of kinetic energy of the cloud to the internal energy of the background gas is very similar to the adiabatic models described above, indicating that efficient cooling within the clouds does not have a strong effect upon the energy deposition rate.

Fragmentation of the cloud also occurs in Model 3. The efficient cooling enhances the density contrast between the cloud and 