Diane A. Verner

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We present new calculations and analytic fits to the rates of radiative recombination towards H-like, He-like, Li-like and Na-like ions of all elements from H through Zn (Z = 30). The fits are valid over a wide range of temperature, from 3 K to 109 K. Subject headings: atomic data – atomic processes
We present a complete set of analytic fits to the non-relativistic photoionization cross sections for the ground states of atoms and ions of elements from H through Si, and S, Ar, Ca, and Fe. Near the ionization thresholds, the fits are based on the Opacity Project theoretical cross sections interpolated and smoothed over resonances. At higher energies, the(More)
The calculation of accurate collision strengths for atomic transitions has been a long standing problem in quantitative spectroscopy. Most modern calculations are based on the R-matrix method and problems pertaining to the use of this method have led to a discussion of the accuracy of these results. More in particular, based on an analysis of the spectra of(More)
We reexamine the spectroscopic underpinnings of recent suggestions that [O I] and [Fe II] lines from the Orion H II region are produced in gas where the iron-carrying grains have been destroyed and the electron density is surprisingly high. Our new observations show that previous detections of [O I] 5577 were dominated by telluric emission. Our limits are(More)
The enrichment of Fe, relative to alpha-elements such as O and Mg, represents a potential means to determine the age of quasars and probe the galaxy formation epoch. To explore how Fe II emission in quasars is linked to physical conditions and abundance, we have constructed a 830-level Fe II model atom and investigated through photoionization calculations(More)
We list wavelengths, statistical weigths and oscilla-tor strengths for 2249 spectral lines arising from the ground states of atoms and ions. The compilation covers all wavelengths longward of the Heii Lyman limit at 227.838 A and all the ion states of all elements from hydrogen to bismuth (Z = 83) for which reliable data are known. We assign experimental(More)
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