LMC HII REGION LUMINOSITIES VERSUS OBSERVED IONIZING STARS

We use the stellar census of OB associations in the Large Magellanic C loud (LMC) to predict the H alpha luminosities of the host I-III regio ns, based on results from stellar atmosphere models. These values are compared to the observed I-III region luminosities, yielding an estima te for the mean fraction of H-ionising photons that escape the local n ebulae in this sample. We formally estimate that, overall, 0-51% of th e ionising radiation escapes the local HII regions and is available to ionise the warm, ionised medium in the LMC. We find both nebulae that appear to be density-bounded and ones that appear to be radiation-bou nded.