J/A+A/541/A90 FeX soft X-ray lines (Del Zanna+, 2012)
Atomic data for astrophysics: Fe X soft X-ray lines.
Del Zanna G., Storey P.J, Badnell N.R., Mason H.E.
<Astron. Astrophys. 541, A90 (2012)>
=2012A&A...541A..90D 2012A&A...541A..90D
ADC_Keywords: Atomic physics
Keywords: atomic data - Sun: corona - techniques: spectroscopic
Abstract:
New atomic calculations for Fe X are presented. They focus on the need
to model the soft X-ray spectrum and in particular the line at 94.0Å
which is the dominant contribution to the Solar Dynamics Observatory
(SDO) Atmospheric Imaging Assembly (AIA) 94Å band in quiet Sun
conditions. This line, and others in the band, are due to strong
decays from n=4 levels. We present new large-scale R-matrix (up to
n=4) and distorted-wave (DW, up to n=6) scattering calculations for
electron collisional excitation and compare them to earlier work. We
find significant discrepancies with previous calculations. We show
that resonances significantly increase the cross-sections for
excitations from the ground state to some n=4 levels, in particular to
those in the 3s2 3p4 4s configuration. Cascading from higher levels
is also important. We suggest a new identification for the 3s 3p6
2S1/2 - 3s 3p5 4s 2P3/2 transition, that has a predicted
intensity larger than the decays from the 3s2 3p4 4s levels which
were identified by Edlen in 1936. The results presented here are
relevant to our understanding of transitions from n=4 levels in a
wide range of other ions.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 55 552 Level energies of the RM4 calculation
table2.dat 116 152076 Transition probabilities and thermally averaged
collision strengths for the RM4 calculation
table3.dat 51 1036 Level energies of the DW6 calculation
table4.dat 142 24557 Thermally averaged collision strengths for the
DW6 calculation
table5.dat 32 529145 Transition probabilities for the DW6 calculation
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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3- 5 I3 --- Index [1/552] Level index
7- 24 A18 --- Level Level description
25 A1 --- --- [(]
26 I1 --- 2S+1 [2/6] 2S+1 multiplicity
27 A1 --- --- [)]
28 I1 --- L [0/6] L value
29 A1 --- --- [(]
30- 33 F4.1 --- J [0.5/6.5] J value
34 A1 --- --- [)]
44- 55 F12.4 cm-1 E Target energy (ab initio)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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2- 4 I3 --- i [1/552] Upper level index of the transition
6- 8 I3 --- j [1/552] Lower level index of the transition
10- 17 E8.3 s-1 A Einstein A coefficient
19- 26 E8.3 --- CS20k Averaged collision strength at T=2x104K
28- 35 E8.3 --- CS50k Averaged collision strength at T=5x104K
37- 44 E8.3 --- CS100k Averaged collision strength at T=1x105K
46- 53 E8.3 --- CS200k Averaged collision strength at T=2x105K
55- 62 E8.3 --- CS500k Averaged collision strength at T=5x105K
64- 71 E8.3 --- CS1M Averaged collision strength at T=1x106K
73- 80 E8.3 --- CS2M Averaged collision strength at T=2x106K
82- 90 E9.3 --- CS5M Averaged collision strength at T=5x106K
91- 98 E8.3 --- CS10M Averaged collision strength at T=1x107K
100-107 E8.3 --- CS20M Averaged collision strength at T=2x107K
108-116 E9.3 Ry Elim High-energy limit
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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2- 5 I4 --- Index [1/1036] Level index
7- 24 A18 --- Level Level description
25 A1 --- --- [(]
26 I1 --- 2S+1 [2/6] 2S+1 multiplicity
27 A1 --- --- [)]
28 A1 --- L [SPDFGHI] L value
29 A1 --- --- [(]
30- 33 F4.1 --- J [0.5/6.5] J value
34 A1 --- --- [)]
43- 49 I7 cm-1 E Target energy (ab initio)
50- 51 A2 --- --- [.0]
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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4- 5 I2 --- i [1/24] Lower level index of the transition
7- 10 I4 --- j [2/1036] Upper level index of the transition
12- 21 E10.4 [-] loggf Oscillator strength (gf value)
23- 32 E10.4 Ry E Energy difference between levels
34- 43 E10.4 --- CS2k Averaged collision strength at T=2x104K
45- 54 E10.4 --- CS5k Averaged collision strength at T=5x104K
56- 65 E10.4 --- CS10k Averaged collision strength at T=1x105K
67- 76 E10.4 --- CS20k Averaged collision strength at T=2x105K
78- 87 E10.4 --- CS50k Averaged collision strength at T=5x105K
89- 98 E10.4 --- CS100k Averaged collision strength at T=1x106K
100-109 E10.4 --- CS200k Averaged collision strength at T=2x106K
112-121 E10.4 --- CS500k Averaged collision strength at T=5x106K
123-132 E10.4 --- CS1M Averaged collision strength at T=1x107K
133-142 E10.4 --- CS2M Averaged collision strength at T=2x107K
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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3- 5 I3 --- i [0/999] Lower level index of the transition
7- 10 I4 --- j [2/1036] Upper level index of the transition
13- 21 E9.4 [-] loggf Oscillator strength (gf value)
24- 32 E9.4 s-1 A Einstein A coefficient
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Acknowledgements:
Giulio Del Zanna, gdelzanna(at)spd.aas.org
(End) Patricia Vannier [CDS] 29-Jun-2012