Metallicity, ionization parameter, and pressure variations of HII
  regions in the TYPHOON spiral galaxies
  We present a spatially-resolved HII region study of the gas-phase
metallicity, ionization parameter, and ISM pressure maps of 6 local
star-forming and face-on spiral galaxies from the TYPHOON program.
Self-consistent metallicity, ionization parameter, and pressure maps are
calculated simultaneously through an iterative process to provide useful
measures of the local chemical abundance and its relation to localized ISM
properties. We constrain the presence of azimuthal variations in metallicity by
measuring the residual metallicity offset $\Delta$(O/H) after subtracting the
linear fits to the radial metallicity profiles. We however find weak evidence
of azimuthal variations in most of the galaxies, with small (mean 0.03 dex)
scatter. The galaxies instead reveal that HII regions with enhanced and reduced
abundances are found distributed throughout the disk. While the spiral pattern
plays a role in organizing the ISM, it alone does not establish the relatively
uniform azimuthal variations we observe. Differences in the metal abundances
are more likely driven by the strong correlations with the local physical
conditions. We find a strong and positive correlation between the ionization
parameter and the local abundances as measured by the relative metallicity
offset $\Delta$(O/H), indicating a tight relationship between local physical
conditions and their localized enrichment of the ISM. Additionally, we
demonstrate the impact of unresolved observations on the measured ISM
properties by rebinning the datacubes to simulate low-resolution (1 kpc)
observations, typical of large IFU surveys. We find that the ionization
parameter and ISM pressure diagnostics are impacted by the loss of resolution
such that their measured values are larger relative to the measured values on
sub-HII region scales.
