The ionization equilibrium of iron in H II regions
Abstract
We study the ionization equilibrium of Fe using photoionization models that incorporate improved values for the ionization and recombination cross-sections and the charge-exchange rates for the Fe ions. The previously available photoionization models predict concentrations of Fe3+ which are a factor of 3-8 higher than the values inferred from emission lines of [Fe III] and [Fe IV]. Our new models reduce these discrepancies to factors of 2-5. We discuss the possible reasons behind the remaining discrepancies and present an updated ionization correction factor for obtaining the Fe abundance from the Fe++ abundance.
Keywords
Cite
@article{arxiv.astro-ph/0312246,
title = {The ionization equilibrium of iron in H II regions},
author = {M. Rodriguez and R. H. Rubin},
journal= {arXiv preprint arXiv:astro-ph/0312246},
year = {2007}
}
Comments
4 pages, 1 figure, extended version of the paper to be published in "Recycling intergalactic and interstellar matter", IAU Symposium Series, Vol. 217, 2004, P.-A. Duc, J. Braine and E. Brinks, eds