  We describe two means by which XSTAR, a code which computes physical
conditions and emission spectra of photoionized gases, has been parallelized.
The first is pvm_xstar, a wrapper which can be used in place of the serial
xstar2xspec script to foster concurrent execution of the XSTAR command line
application on independent sets of parameters. The second is PModel, a plugin
for the Interactive Spectral Interpretation System (ISIS) which allows
arbitrary components of a broad range of astrophysical models to be distributed
across processors during fitting and confidence limits calculations, by
scientists with little training in parallel programming. Plugging the XSTAR
family of analytic models into PModel enables multiple ionization states (e.g.,
of a complex absorber/emitter) to be computed simultaneously, alleviating the
often prohibitive expense of the traditional serial approach. Initial
performance results indicate that these methods substantially enlarge the
problem space to which XSTAR may be applied within practical timeframes.
