Specific column density ratios may be used as diagnostic probes
of the ionization state, temperature, and metallicity in radiatively
cooling gas.
Online Tool:
In the figures generated here (see, for example, figure 10 in
text)
we display "cooling trajectories" for an ionic ratio versus an absolute
column density, for a fixed hydrogen column density
NH=1020 cm-2.
Use the drop-down lists to select the ratio to be displayed along the
y-axis, and the column to be displayed along the x-axis.
Use the buttons on the right to select whether results should be displayed for isochoric or isobaric cooling. Then press "Submit Query". Results would appear in a couple of minutes.
The gas temperature is represented by color
along the curves, from hot (red) to cool (blue).
Panel (a) shows the behavior
for CIE, where we assume Z=1.
Panels (b)-(f) are
for non-equilibrium isochoric cooling, for Z from
10-3 to 2.
