Resolution and accuracy of resonances in R-matrix cross sections

O VI + hnu. Surprisingly however, the effect on the monochromatic and the mean Rosseland and Planck bound-free opacities is relatively small, but may be potentially significant.
11 pages, 4 figures, Journal of Physics B -->
DOI: 10.48550/arxiv.astro-ph/0406472
Přístupová URL adresa: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::650c49aa2d56e007f6c990967aa621ca
Rights: OPEN
Přírůstkové číslo: edsair.doi.dedup.....650c49aa2d56e007f6c990967aa621ca
Autor: Hong Lin Zhang, Sultana N. Nahar, Anil K. Pradhan, Franck Delahaye
Rok vydání: 2004
Předmět:
DOI: 10.48550/arxiv.astro-ph/0406472
Popis: We investigate the effect of resonances in photoionization and recombination cross sections computed using the R-matrix method. Photoionization and recombination rates derived from high-resolution cross sections for oxygen ions are compared with earlier works with less resolution and accuracy, such as in the widely used Opacity Project data. We find significant differences in photoionization rates for O II metastable states, averaged over Planck functions corresponding to ionizing radiation fields, with respect to the intrinsic accuracy of the calculations and improved resolution. Furthermore, for highly charged ions other physical effects are also important. Recombination rate coefficients, averaged over a Maxwellian distribution, are extremely sensitive to the position and resolution of near-threshold resonances, and radiation damping, in (e + O VII) --> O VI + hnu. Surprisingly however, the effect on the monochromatic and the mean Rosseland and Planck bound-free opacities is relatively small, but may be potentially significant.
11 pages, 4 figures, Journal of Physics B
Databáze: OpenAIRE
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