Astron. Astrophys. Suppl. Ser. 141, 285-296

Atomic data from the IRON Project

XL. Electron impact excitation of the Fe  XIV EUV transitions

P.J. Storey¹ - H.E. Mason² - P.R. Young²

Send offprint request: P.J. Storey

1 - Department of Physics and Astronomy, Gower Street, London WC1E 6BT, UK
2 - Department of Applied Mathematics and Theoretical Physics, Silver Street, Cambridge CB3 9EW, UK

Received April 26; accepted August 26, 1999

Abstract:

We calculate collision strengths and thermally averaged collision strengths for electron excitation between the forty energetically lowest levels of Fe¹³⁺. The scattering calculation is more complete than any previous work on this ion and significant differences are found in the excitation rates for many of the extreme ultra-violet (EUV) transitions, compared to earlier work. A detailed comparison is made between predicted line intensity ratios and those observed in solar coronal spectra which shows that several outstanding discrepancies are resolved by the new atomic data.

Key words: Sun: corona; atomic data; UV radiation