VI/136 Dielectronic Recombination Lines of C+ - SS1 (Sochi+, 2013)
Dielectronic Recombination Lines of C+.
Sochi T., Storey P.J.
<Atomic Data and Nuclear Data Tables, DOI: 10.1016/j.adt.2012.10.002 (2013)>
=2013yCat.6136....0S 2013yCat.6136....0S
ADC_Keywords: Atomic physics
Keywords: C+ ion - atomic transition - atomic spectroscopy - line list -
intermediate coupling - dielectronic recombination - radiative decay -
oscillator strength - bound state - resonance - emissivity -
recombination rate coefficient - R-matrix - Autostructure -
Emissivity code
Abstract:
A computed list of transition lines for the atomic ion C+ is
generated using R-matrix [1], Autostructure [2] and Emissivity [3]
codes. These lines are produced by dielectronic recombination and
subsequent cascade decays of the low-lying autoionizing states above
the threshold of C2+1Se with a principal quantum number n<5 for
the captured electron. The line list contains 6187 optically-allowed
transitions which include many C II lines observed in the astronomical
spectra [4]. Beside the transition lines, the data also include level
energies for the bound and resonance states, radiative transition
probabilities, recombination rate coefficients, and oscillator
strengths. A 26-term C2+ atomic target was used within an
intermediate coupling scheme in the production of these data. The
theoretical results for energy and fine structure splitting agree very
well with the available experimental data for both resonances and
bound states. The data were also validated by comparison to
theoretical data previously reported in the literature which include
radiative transition probabilities, effective dielectronic
recombination rate coefficients and autoionization probabilities.
Description:
The data consist of four files as detailed below:
1. 'resemis.txt' File: This is the file containing the data for the
resonances. The file contains four main sections:
A. The first section starts with a comment line followed by the number
of resonances followed by a number of text lines matching the number
of resonances. Each one of these lines contains an index identifying
the resonance, the energy position of the resonance in z-scaled Ryd,
the width in z-scaled Ryd, the configuration, term, 2J, parity, a flag
for marking the energy position data as experimental (1) or
theoretical (0), and a flag marking the resonance to be included in
the emissivity and recombination calculations (1) or not (0).
B. The second section starts with a comment which is followed by the
number of the bound state symmetries. The oscillator strengths
(f-values) for the free-bound transitions then follow in sections
according to the symmetries of the bound states, so the number of the
f-value sections is the same as the number of bound state symmetries.
Each section of the f-values is headed by a line containing 2J, parity
and the number of bound states in that symmetry. This is followed by a
two-dimensional array of f-values where the columns stand for the
resonances as ordered previously, whereas the rows are for the bound
states of the given symmetry. For the transitions which are forbidden
by the electric dipole rules for J and parity, the f-values are set to
zero. The reason for this is to comply with the 'Emissivity' code [3]
format to consider possible extension to include transitions other
than those allowed by the electric dipole.
C. The third section also starts with an explanatory comment. The data
for the photon energy at resonance position, which correspond to the
f-values data in the previous section, then follow, sectioned and
formatted as for the f-values data. The photon energy data are in Ryd.
D. The last section starts with a comment as in the previous sections.
The weighted oscillator strengths (gf) for the free-free transitions
are then included in a two-dimensional array where the columns stand
for the odd resonances while the rows stand for the even ones.
2. 'elevemis.txt' File: This file contains the bound states data. The
file starts with a comment followed by the number of bound states
symmetries. This is followed by a data block for each symmetry. Each
block is headed by a line containing 2J, parity and the number of
bound states in that symmetry. Next, a number of text lines as the
number of bound states in that symmetry follow. Each line contains an
index identifying the state, the energy of the bound state in z-scaled
Ryd, the effective quantum number, the configuration, term and a flag
for marking the energy data as experimental (1) or theoretical (0).
3. 'fvalue.txt' File: This file, which contains the weighted
oscillator strengths (gf) for the bound-bound transitions in length
and velocity forms, is generated by the stage STGBB of the R-matrix
code and is included with no modification apart from adding extra
data. The added data are the bound-bound weighted oscillator strengths
for the eight uppermost bound states, namely the 1s22s2p(3Po)3d
4Fo and 4Do levels, which were generated by Autostructure [2]
and then added manually to the 'FVALUE.dat' file. The reason is that
these states have very large effective quantum numbers and hence are
out of range of the R-matrix code validity.
4. 'transitions.txt' File: This is the main output file of the
'Emissivity' code [3]. The file starts with a number of text lines
summarizing input parameters and statistical information, followed by
a few commentary lines explaining the symbols and units. This is
followed by a number of data lines matching the number of transitions
(6187). The data for each transition include an index identifying the
transition, status (FF, FB or BB transition where F stands for Free
and B for Bound), two joined boolean flags describing the experimental
state of the energy data of the upper and lower levels ('0' for
theoretical data and '1' for experimental), the attributes of the
upper and lower levels (configuration, term, 2J and parity),
wavelength in vacuum (in Angstrom), wavelength in air (which is only
for lambda > 2000 Angstrom), the radiative transition probability (in
s-1), and the recombination coefficients (in m3.s-1)
corresponding to the given 10-based logarithmic temperatures (2.0-4.6
in steps of 0.1). The number density of ions (N_i) and electrons (N_e)
for these data is 1E+10(m-3).
It should be remarked that the first three files are in the format of
the input files of Emissivity code [3]. The reason for this is to
enable other researchers to produce transition data for different
input parameters (such as temperature and number density) or produce
other types of data such as emissivity, normalized emissivity, and
decay routes, as well as performing analysis on observational data
related to C II transitions. The oscillator strengths and the
resonance and bound states data may also be useful to some. All these
aspects are detailed in the Emissivity code paper [3] and manual.
Other relevant details can also be found in [4].
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
trans.dat 453 6187 Recombination coefficients
elevemis.txt 512 21 Bound states data (original file)
fvalue.txt 31 2908 Weighted oscillator strengths data (original file)
resemis.txt 512 210 Resonances data (original file)
transitions.txt 512 5513 Recombination coefficients data (original file)
--------------------------------------------------------------------------------
See also:
VI/119 : High accuracy computed water line list - BT2 (Barber+, 2006)
VI/130 : High accuracy computed H2D+ line list - ST1 (Sochi+, 2010)
Byte-by-byte Description of file: trans.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- Index [1/6187] Index
8- 9 A2 --- Stat Status (FF, FB or BB transition where "F" stands
for Free and "B" for Bound)
14- 15 I02 --- Exp [00/11] Experimental state of the energy data of
the upper and lower levels ('0' for theoretical
data and '1' for experimental: 00, 01, 10 or 11)
20- 37 A18 --- Conf1 Lower level Configuration term
41- 42 I2 --- 2J1 [1/11] Lower level 2J value
44 I1 --- P1 [0/1] Lower level parity
50- 51 A2 --- --- [->]
57- 74 A18 --- Conf2 Upper level Config Term 2J term
78- 79 I2 --- 2J2 [1/11] Upper level 2J value
81 I1 --- P2 [0/1] Upper level parity
86- 96 F11.2 0.1nm lam.v [450/5.4e+7] Wavelength in vacuum
101-111 F11.2 0.1nm lam.a [2000/5.4e+7]?=- Wavelength in air
(only for λ>200nm)
116-128 E13.4 s-1 Gamma Radiative transition probability, Gammarul
131-141 E11.4 m3/s RC2.0 Recombination coefficient at logT=2.0
143-153 E11.4 m3/s RC2.1 Recombination coefficient at logT=2.1
155-165 E11.4 m3/s RC2.2 Recombination coefficient at logT=2.2
167-177 E11.4 m3/s RC2.3 Recombination coefficient at logT=2.3
179-189 E11.4 m3/s RC2.4 Recombination coefficient at logT=2.4
191-201 E11.4 m3/s RC2.5 Recombination coefficient at logT=2.5
203-213 E11.4 m3/s RC2.6 Recombination coefficient at logT=2.6
215-225 E11.4 m3/s RC2.7 Recombination coefficient at logT=2.7
227-237 E11.4 m3/s RC2.8 Recombination coefficient at logT=2.8
239-249 E11.4 m3/s RC2.9 Recombination coefficient at logT=2.9
251-261 E11.4 m3/s RC3.0 Recombination coefficient at logT=3.0
263-273 E11.4 m3/s RC3.1 Recombination coefficient at logT=3.1
275-285 E11.4 m3/s RC3.2 Recombination coefficient at logT=3.2
287-297 E11.4 m3/s RC3.3 Recombination coefficient at logT=3.3
299-309 E11.4 m3/s RC3.4 Recombination coefficient at logT=3.4
311-321 E11.4 m3/s RC3.5 Recombination coefficient at logT=3.5
323-333 E11.4 m3/s RC3.6 Recombination coefficient at logT=3.6
335-345 E11.4 m3/s RC3.7 Recombination coefficient at logT=3.7
347-357 E11.4 m3/s RC3.8 Recombination coefficient at logT=3.8
359-369 E11.4 m3/s RC3.9 Recombination coefficient at logT=3.9
371-381 E11.4 m3/s RC4.0 Recombination coefficient at logT=4.0
383-393 E11.4 m3/s RC4.1 Recombination coefficient at logT=4.1
395-405 E11.4 m3/s RC4.2 Recombination coefficient at logT=4.2
407-417 E11.4 m3/s RC4.3 Recombination coefficient at logT=4.3
419-429 E11.4 m3/s RC4.4 Recombination coefficient at logT=4.4
431-441 E11.4 m3/s RC4.5 Recombination coefficient at logT=4.5
443-453 E11.4 m3/s RC4.6 Recombination coefficient at logT=4.6
--------------------------------------------------------------------------------
Acknowledgements:
Taha Sochi: t.sochi(at)ucl.ac.uk
Peter J. Storey: pjs(at)star.ucl.ac.uk
References:
[1] Berrington K.A., Eissner W.B. and Norrington P.H. (1995) RMATRX1:
Belfast atomic R-matrix codes.
Computer Physics Communications 92(2): 290-420.
[2] Badnell N.R. (2013) Autostructure writeup on the world wide web.
URL: http://amdpp.phys.strath.ac.uk/autos/ver/WRITEUP.
[3] Sochi T. (2010) Emissivity: A program for atomic transition
calculations. Communications in Computational Physics, 7(5): 1118-1130.
[4] Storey P.J., Sochi T. (2013) Electron Temperatures and Free-Electron
Energy Distributions of Nebulae from C II Dielectronic Recombination Lines
(2013MNRAS.430..599S 2013MNRAS.430..599S)
(End) Taha Sochi [Univ. College London], Patricia Vannier [CDS] 05-Aug-2013