1. Eliminating error in the chemical abundance scale for extragalactic H ii regions.
- Author
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López-Sánchez, Á. R., Dopita, M. A., Kewley, L. J., Zahid, H. J., Nicholls, D. C., and Scharwächter, J.
- Subjects
H II regions (Astrophysics) ,ASTROPHYSICS ,MEASUREMENT errors ,ASTRONOMICAL models ,ELECTRON temperature ,DATA analysis - Abstract
ABSTRACT In an attempt to remove the systematic errors which have plagued the calibration of the H ii region abundance sequence, we have theoretically modelled the extragalactic H ii region sequence. We then used the theoretical spectra so generated in a double-blind experiment to recover the chemical abundances using both the classical electron temperature + ionization correction factor technique and the technique which depends on the use of strong emission lines (SELs) in the nebular spectrum to estimate the abundance of oxygen. We find a number of systematic trends, and we provide correction formulae which should remove systematic errors in the electron temperature + ionization correction factor technique. We also provide a critical evaluation of the various semi-empirical SEL techniques. Finally, we offer a scheme which should help to eliminate systematic errors in the SEL-derived chemical abundance scale for extragalactic H ii regions. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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