  In this paper, we present an overview of our method of constructing a family
of models for the far-infrared, sub-millimeter, and millimeter (FIR/sub-mm/mm)
line emission of molecular and atomic gas surrounding massive star formation in
starburst galaxies. We show the results of a case study, an expanding
supershell centered around a massive star cluster with a particular set of
input parameters and its application to nearby starburst galaxy M 82. This set
of models can be used not only to interpret the observations of FIR/sub-mm/mm
line emission from molecular and atomic gas, but also to investigate the
physical environment and the initial cloud conditions in massive star forming
regions as well as the ages of the starbursts through simulations for a wide
range of input parameters. Finally, we discuss limitations of our models, and
outline future work.
