Astron. Astrophys. Suppl. Ser.
Volume 143, Number 3, May I 2000
|Page(s)||483 - 489|
|Published online||15 May 2000|
Atomic data from the IRON Project*
XLII. Electron impact excitation of Fe xxi
Institut für Astronomie und Astrophysik, Scheinerstr. 1, D-81679 München, Germany
2 UMR 8631 (associée au CNRS et à l'Université Paris 7) et DAEC, Observatoire de Paris, F-92195 Meudon, France
Send offprint request to: K. Butler
Accepted: 8 February 2000
Collision strengths and collisional rate parameters are provided for transitions among the and 2p levels of C-like Fe xxi. The data have been computed in a 52-state Breit-Pauli approximation thus accounting for the most prominent relativistic effects. An R-matrix close-coupling calculation comprising partial wave contributions up to and of order 8000 energy points in the range up to 260 Ryd gave cross sections expected to be accurate to better than 20% for transitions among the levels.
Key words: atomic data / atomic processes
Detailed tables of the present data are available in electronic form at the CDS via anonymous ftp to 220.127.116.11 or via http://cdsweb.u-strasbg.fr/Abstract.html. Table 3 is only available in electronic form at the CDS.
© European Southern Observatory (ESO), 2000