New Improved Calibration Relations for the Determination of Electron Temperatures and Oxygen and Nitrogen Abundances in H II Regions
Abstract
New improved empirical calibrations for the determination of electron temperatures and oxygen and nitrogen abundances in H II regions from the strong emission lines of oxygen, nitrogen, and sulfur are given. They are derived using spectra of H II regions with measured electron temperatures as calibrating data. Calibration relations are given separately for three classes of H II regions: cool, warm, and hot ones. Criteria for assigning a H II region to one of these classes are suggested. We find that classification ambiguities arise only in the case of hot H II regions with enhanced nitrogen abundances. The derived calibrations provide reliable abundances for H II regions: the mean difference between oxygen abundances determined from the calibrations and Te -based oxygen abundances is ~0.075 dex, while it is ~0.05 dex for nitrogen abundances.
- Publication:
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The Astrophysical Journal
- Pub Date:
- September 2010
- DOI:
- 10.1088/0004-637X/720/2/1738
- Bibcode:
- 2010ApJ...720.1738P
- Keywords:
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- galaxies: abundances;
- galaxies: evolution;
- galaxies: ISM;
- H II regions