The Most Massive Stars do the Most Damage: Improving Stellar and Photoionized Models in Nearby HII Regions

Integral field spectroscopy with instruments such as MUSE provide an extraordinary dataset to study the resolved spatial and spectral properties of ionized HII regions in nearby galaxies. Having self-consistent stellar tracks and stellar atmosphere models are crucial to accurately interpret observations of HII regions. To date, only a handful of stellar evolution models are available and they all use the same metallicity abundances. We know now that the assumed metallicity abundances greatly impacts the relative scaling of emission lines ratios for the HII regions, and the input modeled elemental abundances will have a non-insignificant impact on the resulting measurements, such as metallicity, geometry, temperature, and ionization parameter. We now have empirical, physically realistic HII region abundance sets that we use to create stellar models that are self-consistent with their stellar atmosphere modeling. We will present the impact of the different assumed elemental abundances has on the observable spectral energy distributions and how this impacts our understanding of the evolution of metallicity and star formation over cosmic time.