©1995. Astronomical Society of the Pacific
107: 896-906, 1995 September
Richard A. Shaw
Space Telescope Science Institute (1), 3700 San Martin Dr.,
Baltimore, MD 21218
Electronic mail: shaw@stsci.edu
Reginald J. Dufour
Dept. of Space Physics & Astronomy, Rice University, Houston,
TX 77251
Electronic mail: rjd@rice.edu
Received 1995 March 3; accepted 1995 May 26
) and density (N
).
The package is based on the five-level atom program
developed by De Robertis, Dufour and Hunt (1987), but it includes diagnostics
from a greater set of ions and emission lines, most particularly those in
the satellite ultraviolet that are now observable.
Two of the applications make use of a 3-zone nebular model to derive T and N
simultaneously in separate zones of low-, intermediate-, and
high-ionization. These applications are useful for calculating nebular
densities and temperatures directly from the traditional diagnostic line
ratios, either to provide some reasonable input parameters for a more
complicated physical model, or to calculate ionic abundances (or other
quantities) within some simplifying assumptions. Examples of the utility
of these diagnostics for real nebulae are presented.
Subject headings: Computing and Data Analysis; Interstellar Medium and Nebulae