Astronomy Astrophysics Atomic data from the IRON Project LI. Electron impact excitation of Fe IX?

Abstract. We calculate collision strengths and thermally averaged collision strengths for electron excitation between the one hundred and forty energetically lowest levels of Fe8+. The scattering target is more elaborate than in any earlier work and large increases are found in the excitation rates among the levels of the 3s23p53d electron configuration due to resonance series that have not been considered previously. The implications for solar and stellar spectroscopy have been discussed elsewhere (Storey & Zeippen 2001). We correct some errors that were made in generating the figures given in that paper and present corrected versions. Key words. Sun: general – atomic data – Sun: UV radiation 1. Dedication Maryvonne Le Dourneuf had started working on this project when an accident caused her untimely death in November 1997. This paper is dedicated to her memory