Two tasks provide a simple IRAF-style command-line interface for calculating
nebular diagnostics for a single ion. The *temden* task calculates
N
given T
, or T
given N
, for one of several ions. (See example 1 in
Figure 2 .) Note that a simple algebraic expression can be used
to specify the ratio of the relevant diagnostic lines. The *ionic* task
computes and displays the line emissivities for all transitions between each
of the five lowest levels. Optionally, this task will display the level
populations and critical densities (see Eq. 4 and Eq. 5 )for these levels.
If the wavelength and flux (on the scale H) of one of these
lines is also provided, *ionic* will also compute the H emissivity (see
Eq. 6 ) and ionic abundance (see Eq. 7 ).
Note that the ionic abundance can be computed from the sum of two or more
line intensities if the wavelength tolerance (i.e., the `wv_toler`
parameter) is set large enough.

Thu Aug 8 17:23:06 EDT 1996