A&A Supplement series, Vol. 123, May II 1997, 159-171
Received September 16; accepted September 17, 1996
M.E. Galavís - C. Mendoza - C.J. Zeippen
Send offprint request: C.J. Zeippen
Departamento de Física, Universidad Metropolitana, PO Box 76819, Caracas 1070A, Venezuela - Centro de Física, Instituto Venezolano de Investigaciones Científicas (IVIC), PO Box 21827, Caracas 1020A, Venezuela
URA 173 (associée au CNRS et à l'Université Paris 7) et DAEC, Observatoire de Paris, F-92195 Meudon, France
As part of the IRON Project, radiative rates have been calculated for the forbidden transitions within the ground configuration of atoms and ions in the carbon (2s2p) and oxygen (2s2p) isoelectronic sequences for . The atomic structure code SUPERSTRUCTURE was used, which allows for configuration interaction, relativistic effects and semi-empirical term energy corrections. Comparisons are made with previous theoretical datasets for the same sequences. It is shown once again that, to obtain reliable transition probabilities, in particular those of the electric quadrupole type, it is essential to use accurate and consistent experimental transition wavelengths. For the C and O sequences such data are fortunately available from the work of Edlén (1983, 1985). The general accuracy of the present probabilities is rated to be within 10%, with the exception of some electric quadrupole transitions in low-Z ions whose radiative rates are small with an accuracy not better than %.
keywords: atomic data -- atomic processes