Electron-ion recombination of neutral iron

Journal Article · Tue Apr 01 04:00:00 EST 1997 · Astrophysical Journal

DOI:https://doi.org/10.1086/303874· OSTI ID:530009

Nahar, S N; Bautista, M A; Pradhan, A K ^[1]

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1. Department of Astronomy, The Ohio State University, Columbus, Ohio 43210 (United States)

The total and state-specific electron-ion recombination rate coefficients are obtained for FeI. The calculations are carried out using a new ab initio method that incorporates both the radiative and the dielectronic recombination processes in an unified and self-consistent manner. The computations employ the close coupling approximation and the R-matrix method from atomic collision theory. A 52 state close coupling eigenfunction expansion dominated by the states of the ground 3d{sup 6}4s and excited 3d{sup 7}, 3d{sup 6}4p, 3d{sup 5}4s{sup 2}, and 3d{sup 5}4s4p configurations of FeII are used in the present calculations. The important electron correlation and radiation damping effects are included via explicit coupling of autoionization and radiative channels. This is the first detailed atomic calculation for the recombination rates for FeI. The present rates are considerably higher than the radiative recombination rates being used currently in the low-temperature region, T{le}10{sup 4}K, whereas they are about 4 times lower than those given by the Burgess general formula for dielectronic recombination at higher temperatures. The implications of the new recombination rate coefficients and photoionization cross sections for FeI on the ionization structure of iron in the cold neutral interstellar medium are studied. It is found that the ratio of FeII to FeI obtained with the new atomic data increases by a factor of about 3{endash}30 over previous calculations. {copyright} {ital 1997} {ital The American Astronomical Society}

• OSTI ID: 530009
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 479; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ASTROPHYSICS
ELECTRON COLLISIONS
ELECTRONIC STRUCTURE
IRON
IRON IONS
PHOTOIONIZATION
RECOMBINATION
TOTAL CROSS SECTIONS