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New Strong Line Abundance Diagnostics for \HII Regions: Effects of -Distributed Electron Energies and New Atomic Data
Michael A. Dopita, Ralph S. Sutherland, David C. Nicholls +2
Recently, \citet{Nicholls12}, inspired by \emph{in situ} observations of solar system astrophysical plasmas, suggested that the electrons in \HII regions are characterised by a …
Eliminating Error in the Chemical Abundance Scale for Extragalactic HII Regions
Angel R. Lopez-Sanchez, M. A. Dopita, L. J. Kewley +3
In an attempt to remove the systematic errors which have plagued the calibration of the HII region abundance sequence, we have theoretically modeled the extragalactic HII region se…
The Small Isolated Gas Rich Irregular Dwarf (SIGRID) Galaxy Sample: Description and First Results
David C Nicholls, Michael A Dopita, Helmut Jerjen +1
Using an optically-unbiased selection process based on the HIPASS neutral hydrogen survey, we have selected a sample of 83 spatially isolated, gas-rich dwarf galaxies in the southe…