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Opacities for stellar envelopes
We define stellar envelopes to be those regions of stellar interiors in which atoms exist and are not markedly perturbed by the plasma environment. Availability of accurate and extensive atomic data
Ionization structure and spectra of iron in gaseous nebulae and partially ionized zones
The emission spectra and the ionization structure of the low ionization stages of iron, Fe I-Fe IV, in gaseous nebulae are studied. This work includes (i) new atomic data for photoionization cross
[O ii] line ratios
Based on new calculations, we reconfirm the low- and high-density limits on the forbidden finestructure line intensity ratio [O II] I (3729)/I (3726) : limNe→0 = 1.5 and limNe→∞ = 0.35. Employing [O
Rate coefficients for the excitation of infrared and ultraviolet lines in C II, N III, and O IV
New and improved collision strengths and Maxwellian-averaged rate coefficients for temperatures between 1000 and 40,000 K are presented for all the prominent transitions in the spectra of C II, N
A higher-than-predicted measurement of iron opacity at solar interior temperatures
Measurements of wavelength-resolved iron opacity at electron temperatures and electron densities at the solar radiation/convection zone boundary show that wavelength-dependent opacity is 30–400 per cent higher than predicted, which represents roughly half the change in the mean opacity needed to resolve the solar discrepancy.
Electron-Ion Recombination Rate Coefficients, Photoionization Cross Sections, and Ionization Fractions for Astrophysically Abundant Elements. I. Carbon and Nitrogen
We present a comprehensive and self-consistent set of new atomic data for ionization balance in radi- atively and collisionally ionized astrophysical plasmas. Complex resonant phenomena resulting in
Predicted Fe II Emission-Line Strengths from Active Galactic Nuclei
We present theoretical Fe ii emission line strengths for physical conditions typical of active galactic nuclei with broad-line regions. The Fe ii line strengths were computed with a precise treatment