Time-Dependent Ion Fractions

Here we present complete results for the time-dependent ion fractions, for both isochoric and isobaric evolutions, for a wide range of metallicities. For a low-density gas, the ion fractions are independent of the gas density or pressure. Here we assume that the gas is cooling from an initially hot, T>5x106K, equilibrium state.

Download tables of time-dependent ion fractions versus temperature: (or get equilibrium ion fractions)

Isochoric Cooling Isobaric Cooling
Z=10-3 html,  ASCII (text). Z=10-3 html,  ASCII (text).
Z=10-2 html,  ASCII (text). Z=10-2 html,  ASCII (text).
Z=10-1 html,  ASCII (text). Z=10-1 html,  ASCII (text).
Z=1 html,  ASCII (text). Z=1 html,  ASCII (text).
Z=2 html,  ASCII (text). Z=2 html,  ASCII (text).

Online Tool:
Calculate ion fractions at user-supplied temperature:

Get Ion Fraction at T= K, assuming:
   Collisional ionization equilibrium (CIE).
   Time-dependent cooling, of Z= times solar metallicity gas.


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Constructed: June 2006, Orly Gnat