Phase Diagrams

February 3, 2016

Simulation paratmeters: A sphere of radius , and density is placed in pressure equilibrium with a hot wind. The wind parameters are chosen at a distance of : , , and . The Mach number of the wind at this point is .

Below is a snapshot showing a density projection from the sphere-wind simulation at 100 kyr. The dimensions of the simulation volume are pc, with a cloud resolution of 32 cells / . Numbered rectangles show regions of the simulation that will be highlighted in density-temperature phase diagrams below.

In the density-temperature phase diagrams below, in addition to the gas in the simulation volume, I have also plotted a dashed line showing where heating balances cooling in the Cloudy models, as well as a solid line showing the density-temperature relationship for an adiabatic expansion of cloud material, assuming the constant pressure set in the initial conditions.

A density-temperature phase diagram using the full simulation volume:

A velocity-temperature phase diagram using the full simulation volume:

A velocity-weighted density-temperature phase diagram using the full simulation volume:

In order to more clearly see how the regions of the phase diagram are populated, I have also plotted density-temperature diagrams which correspond to the regions marked on the initial snapshot (shown again here).