J/A+A/433/731 Fe XII Benchmarking atomic data (Del Zanna+, 2005)
Benchmarking atomic data for astrophysics: Fe XII.
Del Zanna G., Mason H.E.
<Astron. Astrophys. 433, 731 (2005)>
=2005A&A...433..731D 2005A&A...433..731D
ADC_Keywords: Atomic physics
Keywords: atomic data - line: identification
Abstract:
We use recently calculated electron collisional data by Storey et al.
(2005A&A...433..717S 2005A&A...433..717S) for Fe XII (n=3 configurations) to build a model
ion to compare to spectroscopic observations of the solar corona and
laboratory measurements. We review all the line identifications of the
brightest lines, by comparing both wavelengths and line intensities.
The presence of blends in different plasma conditions is highlighted.
A large number of new energy levels and line identifications are
proposed. In particular, we identify the electric quadrupole
4P5/2-4^F9/2 transition with the bright coronal line observed at
592.6Å, previously unidentified. This line, when observed with the
1242.0, 1349.5 UV forbidden lines, is a good density diagnostic over a
large range of electron densities. We also indicate the best spectral
lines to be used for density diagnostics or instrument calibration.
From various combinations of lines we obtain electron densities that
are significantly different from those published in the previous
literature. Some examples are provided. The agreement between theory
and experimental data in terms of wavelengths, line intensities and
level lifetimes is excellent.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 104 143 Fine Structure Energy table with spectroscopic
identifications
table3.dat 63 8377 Full set of wavelengths, oscillator strengths (gf),
and transition probabilities (A)
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See also:
www.nist.gov : NIST Home Page
J/A+A/422/731 : Fe X Benchmarking atomic data (Del Zanna+, 2004)
J/A+A/430/331 : Fe XXIII Benchmarking atomic data (Chidichimo+, 2005)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Index Energy level index
5- 63 A59 --- Conf Configuration and percentage mixing
64 I1 --- 2S+1 Spin 2S+1
66- 67 A2 --- L Angular momentum L
68- 71 A4 --- J Total angular momentum J
73 A1 --- P Parity (odd/even)
75- 82 F8.1 cm-1 E Energy (best estimate)
84- 86 I3 cm-1 e_E Uncertainty on Eb
88- 92 I5 cm-1 E-Enist ? Energy difference.
Enist: energy as in the NIST database.
94- 99 I6 cm-1 E-Ecc Energy difference.
Ecc: energy from the scattering calculation
101-104 I4 cm-1 E-Ess Energy difference.
Ess: energy from SUPERSTRUCTURE, with term
energy corrections
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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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1- 3 I3 --- i index of the lower level (see Table2.dat)
4- 7 I4 --- j index of the upper level (see Table2.dat)
9- 19 F11.3 0.1nm lambda Wavelength calculated from the best energy
21- 31 F11.3 0.1nm e_lambda Estimated uncertainty on the wavelength
33- 41 E9.4 --- gf Weighted oscillator strengths
44- 52 E9.4 s-1 A Transition probability
54- 63 A10 --- Trans Type of transition (1)
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Note (1): Type of transition are:
E1 = electric dipole
M1 = magnetic dipole
E2 = electric quadrupole
M2 = magnetic quadrupole
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Acknowledgements: Giulio Del Zanna, G.Del-Zanna(at)damtp.cam.ac.uk
(End) Patricia Vannier [CDS] 13-Jan-2005