NEBULAR.ionic Task

Use this form to run the STSDAS task nebular.ionic. This task can calculate the level populations, critical densities, and line emissivities for a selected ion, given the electron temperature and density. If the flux and wavelength of a particular emission line are also given, this task will calculate the ionic abundance, relative to H+. Simply fill in the appropriate information below and press the |Perform Calculation| button to calculate the line emissivities. Detailed help is available in the STSDAS on-line documentation, but bear in mind that the interface for this form is different.

Select an atom:

Specify a spectrum (e.g., for [O III] use "III"):


Enter a value for the electron temperature:

Enter a value for the electron density:

Optional Parameters

Enter the wavelength of an emission line and an associated tolerance (Angstroms): Enter the flux of the emission line (on the scale I(H-beta)=100): Print the level populations and critical densities? No Yes

Calculate Line Emissivities

NEBULAR home page Ionic task Temden task

Copyright The Association of Universities for Research in Astronomy, Inc. All Rights Reserved.

Dick Shaw (

Last modified 28 July 1999