Limits to Ionization-Parameter Mapping as a Diagnostic of HII Region Optical Depth

Amit N. Sawant, Eric W. Pellegrini, M. S. Oey +2

We employ ionization-parameter mapping (IPM) to infer the optical depth of HII regions in the northern half of M33. We construct [OIII]$\lambda 5007$/[OII]$\lambda 3727$ and [OIII]$\lambda 5007$/[SII]$…