Atomic data from the Iron Project*
XXVII. Electron impact excitation collision strengths and rate coefficients for Fe IV
Department of Astronomy, The Ohio State University, Columbus, OH 43210, U.S.A.
Send offprint request to: H.L. Zhang
Accepted: 3 March 1997
Collision strengths and maxwellian-averaged rate coefficients have been calculated for 8771 non-vanishing transitions among 140 fine structure levels, dominated by the configurations , , and in Fe IV. Collision strengths are calculated using the R-matrix method with a 49 term close-coupling target expansion for electron energies up to 15 rydbergs. Rate coefficients are tabulated for a wide range of temperatures in which Fe IV is abundant in plasma sources. A brief discussion of the calculations and sample results are given. The present rates for Fe IV are expected to find applications in spectral diagnostics of a variety of astrophysical sources.
Key words: atomic processes / planetary nebulae: general / H II regions
Table 3 for complete data for Fe IV is only available in electronic form at the CDS via anonymous to ftp to cdsarc.u-strasbg.fr (18.104.22.168) or via http://cdsweb.u-strasbg.fr/Abstract.html
© European Southern Observatory (ESO), 1997