J/A+A/486/629 Effective collision strengths for C II (Tayal, 2008)
Electron impact excitation collision strength for transitions in C II.
Tayal S.S.
<Astron. Astrophys. 486, 629 (2008)>
=2008A&A...486..629T 2008A&A...486..629T
ADC_Keywords: Atomic physics
Keywords: atomic data - atomic processes
Abstract:
Oscillator strengths and electron impact excitation collision
strengths for CII lines among the fine-structure levels are
calculated. Thermally averaged collision strengths are presented as a
function of electron temperature for application to astrophysical
plasmas.
An accurate description of the target wave functions has been obtained
in the multiconfiguration Hartree-Fock approach with flexible
non-orthogonal orbitals. The 42 fine-structure levels of the 2s22p,
2s2p2, 2s23l (l=0-2), 2p3, 2s24l (l=0-3), 2s2p3s and 2s25l
(l=0-2) configurations have been included in the scattering
calculation. A second calculation with lowest 35 levels in the
close-coupling expansion has also been carried out to check channel
coupling effects on collision strengths. The continuum functions have
been represented by the use of B-spline basis. The B-spline R-matrix
method in the framework of Breit-Pauli approximation has been used to
investigate the electron impact excitation of forbidden and allowed
transitions in CII.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 91 156 Oscillator strengths and transition probabilities
for dipole-allowed fine-structure transitions in
C II. Comparison is made with the calculation of
Tachiev & Froese Fischer (2000, J. Phys. B33, 2319)
level.dat 20 37 Index and the corresponding level
table5.dat 105 666 Effective collision strengths for fine-structure
transitions in C II
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See also:
J/ApJ/526/544 : Collision strengths in S III (Tayal+, 1999)
J/ApJS/123/295 : Electron impact excitation in Fe XI (Gupta+, 1999)
J/A+A/418/363 : Effective collision strengths for Cl II (Tayal+, 2004)
J/A+A/426/717 : Oscillator strengths for ClII lines (Tayal+, 2004)
J/ApJS/163/207 : Oscillator and collision strengths in NI (Tayal+, 2006)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 26 A26 --- Trans Transition
28 I1 --- 2J J value for the lower level of the transition
30 I1 --- 2J' J value for the upper level of the transition
32- 40 F9.2 0.1nm lambda Wavelength of the transition
42- 48 E7.3 --- fL Present length value of oscillator strength
50- 56 E7.3 --- fV Present velocity value of oscillator strength
58- 65 E8.4 s-1 AL Present length value of transition probability
67- 74 E8.4 --- AV Present velocity value of transition probability
76- 82 E7.3 --- fLTFF ? Length oscillator strength of Tachiev &
Froese Fischer (2000, J. Phys. B33, 2319)
84- 91 E8.4 --- ALTFF ? Length transition probability of Tachiev &
Froese Fischer (2000, J. Phys. B33, 2319)
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Byte-by-byte Description of file: level.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Index [1,37] Index
4- 20 A17 --- Level Level
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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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1- 2 I2 --- i [1,36] i lower level index of the transition
3 A1 ---- --- [-]
4- 5 I2 --- j [2,37] j upper level index of the transition
7- 15 F9.2 0.1nm lambda ? Wavelength of the transition
17- 23 F7.3 --- ECS1E+3 Effective collision strength at Te=1000K
25- 31 F7.3 --- ECS2E+3 Effective collision strength at Te=2000K
33- 39 F7.3 --- ECS3E+3 Effective collision strength at Te=3000K
41- 47 F7.3 --- ECS5E+3 Effective collision strength at Te=5000K
49- 55 F7.3 --- ECS1E+4 Effective collision strength at Te=10000K
57- 63 F7.3 --- ECS2E+4 Effective collision strength at Te=20000K
65- 71 F7.3 --- ECS3E+4 Effective collision strength at Te=30000K
73- 79 F7.3 --- ECS5E+4 Effective collision strength at Te=50000K
80- 87 F8.3 --- ECS1E+5 Effective collision strength at Te=100000K
89- 96 F8.3 --- ECS2E+5 Effective collision strength at Te=200000K
98-105 F8.3 --- ECS4E+5 Effective collision strength at Te=400000K
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Acknowledgements: Swaraj Tayal, stayal(at)cau.edu
History:
* 10-Jul-2008: Original files
* 02-Sep-2008: A corrected version of table5 supplied by the author.
(End) Patricia Vannier [CDS] 29-May-2008