Astron. Astrophys. Suppl. Ser. 137, 157-163

Recombination coefficients for the 5g - 4f transitions of OIII at nebular temperatures and densities

R. Kisielius - P.J. Storey

Send offprint request: P.J. Storey

Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK

Received February 1; accepted February 22, 1999

Abstract:

We calculate effective recombination coefficients for the formation of the 5g - 4f lines of OIII in the intermediate coupling scheme. Photoionization data for the 5g levels calculated using the R-matrix method are used to derive their recombination coefficients. Cascading from higher states is included, allowing for the effects of finite electron density in a hydrogenic approximation. We explicitly include the distribution of population between the two ground levels of O³⁺ in the calculation of the line intensities. The results are presented as a simple programmeable formula allowing the calculation of recombination line intensities for electron temperatures, $T_{\mathrm e}$ in the range $5000~-~20\,000$ K and electron densities, $N_{\mathrm e}$ in the range 10²-10⁶ cm^-3.

Key words: atomic data -- atomic processes -- line: formation -- ISM: H II regions -- ISM: planetary nebulae: general