On the O II ground configuration energy levels
Abstract
The most accurate way to measure the energy levels for the O II 2p^3 ground configuration has been from the forbidden lines in planetary nebulae. We present an analysis of modern planetary nebula data that nicely constrain the splitting within the ^2D term and the separation of this term from the ground ^4S_{3/2} level. We extend this method to H II regions using high-resolution spectroscopy of the Orion nebula, covering all six visible transitions within the ground configuration. These data confirm the splitting of the ^2D term while additionally constraining the splitting of the ^2P term. The energies of the ^2P and ^2D terms relative to the ground (^4S) term are constrained by requiring that all six lines give the same radial velocity, consistent with independent limits placed on the motion of the O+ gas and the planetary nebula data.
Cite
@article{arxiv.astro-ph/0404429,
title = {On the O II ground configuration energy levels},
author = {K. P. M. Blagrave and P. G. Martin},
journal= {arXiv preprint arXiv:astro-ph/0404429},
year = {2009}
}
Comments
20 pages, 3 figures. To be published in ApJ