SYSTEMATICS OF H-II REGION ABUNDANCES IN GALAXIES

Previous studies of gas-phase abundances in disk galaxies have favored late-type field spirals with bright H II regions. Here we report preliminary results from two surveys undertaken to delineate the abundance properties of the full range of galaxy types, luminosities, and structural properties. The galaxies in our sample show a wide range of mean disk abundances and abundance gradients. The mean abundances are correlated with galaxy type, luminosity, and circular velocity along what is predominantly a single-parameter sequence, though it is difficult to determine which of these variables is more fundamentally coupled to the disk abundance. The abundance-luminosity relation for spirals maps almost directly onto those for Magellanic irregular and elliptical galaxies. The slope of the abundance gradient is not closely coupled to Hubble type or luminosity, but appears to be correlated with bar structure.