Diagnostics Diagrams Tools: Ratio-Absolute Diagrams

Specific column density ratios may be used as diagnostic probes of the ionization state, temperature, and metallicity in radiatively cooling gas.

Online Tool:
Select ratio to be displayed on y-axis:

      this will take ~2 minute...


Select column-density to be displayed on x-axis:

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.

Constructed: June 2006, Orly Gnat