  We have modelled the stellar and nebular continua and emission-line intensity
ratios of massive stellar populations in the Antennae galaxy using high
resolution and self-consistent libraries of model HII regions around central
clusters of aging stars. The model libraries are constructed using the stellar
population synthesis code, Starburst99, and photoionisation model, Cloudy. The
Geneva and PARSEC stellar evolutionary models are plugged into Starburst99 to
allow comparison between the two models. Using a spectrum-fitting methodology
that allows the spectral features in the stellar and nebular continua (e.g.
Wolf-Rayet features, Paschen jump), and emission-line diagnostics to constrain
the models, we apply the libraries to the high-resolution MUSE spectra of the
starbursting regions in the Antennae galaxy. Through this approach, we were
able to model the continuum emission from Wolf-Rayet stars and extract stellar
and gas metallicities, ages, electron temperatures and densities of starbursts
by exploiting the full spectrum. From the application to the Antennae galaxy,
we find that (1) the starbursts in the Antennae galaxy are characterised by
stellar and gas metallicities of around solar, (2) the star-forming gas in
starbursts in the Western loop of NGC 4038 appear to be more enriched, albeit
slightly, than the rest of galaxy, (3) the youngest starbursts are found across
the overlap region and over parts of the western-loop, though in comparison,
the regions in the western-loop appear to be at a slightly later stage in
star-formation than the overlap region, and (4) the results obtained from
fitting the Geneva and Parsec models are largely consistent.
