J/ApJS/210/23 Line intensities in CN transitions (Brooke+, 2014)
Einstein A coefficients and oscillator strengths for the A2Π-X2Σ+
(Red) and B2Σ+-X2Σ+ (Violet) systems
and rovibrational transitions in the X2Σ+ state of CN.
Brooke J.S.A., Ram R.S., Western C.M., Li G., Schwenke D.W., Bernath P.F.
<Astrophys. J. Suppl. Ser., 210, 23 (2014)>
=2014ApJS..210...23B 2014ApJS..210...23B
ADC_Keywords: Atomic physics ; Spectroscopy
Keywords: astronomical databases: miscellaneous; methods: laboratory: molecular;
molecular data; opacity; stars: abundances; techniques: spectroscopic
Abstract:
Line strengths have been calculated in the form of Einstein A
coefficients and f-values for a large number of bands of the
A2Π-X2Σ+ and B2Σ+-X2Σ+ systems and
rovibrational transitions within the X2Σ+ state of CN using
Western's PGOPHER program. The J dependence of the transition dipole
moment matrix elements (the Herman-Wallis effect) has been taken into
account. Rydberg-Klein-Rees potential energy functions for the
A2Π, B2Σ+, and X2Σ+ states were computed
using spectroscopic constants from the A2Π-X2Σ+ and
B2Σ+-X2Σ+ transitions. New electronic transition
dipole moment functions for these systems and a dipole moment function
for the X2Σ+ state were generated from high level ab initio
calculations and have been used in Le Roy's LEVEL program to produce
transition dipole moment matrix elements (including their J
dependence) for a large number of vibrational bands. The program
PGOPHER was used to calculate Einstein A coefficients, and a line list
was generated containing the observed and calculated wavenumbers,
Einstein A coefficients and f-values for 290 bands of the
A2Π-X2Σ+ transition with v'=0-22, v"=0-15, 250 bands
of the B2Σ+-X2Σ+ transition with v'=0-15, v"=0-15
and 120 bands of the rovibrational transitions within the
X2Σ+ state with v=0-15. The Einstein A coefficients have
been used to compute radiative lifetimes of several vibrational levels
of the A2Π and B2Σ+ states and the values compared with
those available from previous experimental and theoretical studies.
Description:
Recently, Li et al. (2012JQSRT.113...67L 2012JQSRT.113...67L) calculated Einstein A
coefficients and absolute line intensities for the
E2Π-X2Σ+ transition of CaH using a theoretical TDM
(transition dipole moment) from high level ab initio calculations. In
a similar study, Einstein A coefficients and line strengths have been
calculated for the Swan system of C2 by Brooke et al.
(2013JQSRT.124...11B 2013JQSRT.124...11B). In the present paper we report on the similar
calculations of line intensities of the A2Π-X2Σ+ and
B2Σ+-X2Σ+ transitions of CN, and the
X2Σ+ state rovibrational transitions. These calculations
have been performed using our experimental measurements and
spectroscopic constants (Ram et al. 2010JMoSp.263...82R 2010JMoSp.263...82R,
2006JMoSp.237..225R 2006JMoSp.237..225R), and newly calculated transition dipole moments.
The spectra used for measuring the rotational line positions of the
red (Ram et al. 2010JMoSp.263...82R 2010JMoSp.263...82R) and violet (Ram et al.
2006JMoSp.237..225R 2006JMoSp.237..225R) systems of 12C14N were observed using
different experimental sources including a microwave discharge,
nitrogen afterglow and high temperature furnace. The spectra recorded
using the nitrogen afterglow source provided extensive bands for both
transitions involving high vibrational levels.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 118 195120 List of observed and calculated positions and
calculated intensities of the CN
A2Π-X2Σ+ and
B2Σ+-X2Σ+ systems,
and X2Σ+ state rovibrational transitions
table7.dat 48 665 The vibrational Av'v" and fv'v" values of the
CN A2Π-X2Σ+ and
B2Σ+-X2Σ+ systems,
and X2Σ+ state vibrational transitions
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See also:
J/ApJS/207/26 : MgH in the A2Π-X2Σ+ system (Hinkle+, 2013)
J/ApJS/194/34 : Fourier transform emission spectroscopy of 13C14N (Ram+,
2011)
J/ApJS/95/535 : CO line list for X1Σ+ state (Goorvitch, 1994)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1 A1 --- eS' [ABX] Upper electronic state
3 A1 --- eS'' [X] Lower electronic state
5- 6 I2 --- v' [0/22] Upper state vibrational level
8- 9 I2 --- v'' [0/15] Lower state vibrational level
11- 15 F5.1 --- J' [0.5/115.5] Upper state J level
17- 21 F5.1 --- J'' [0.5/115.5] Lower state J level
23 I1 --- F' [1/2] Upper state F level (1)
25 I1 --- F'' [1/2] Lower state F level (1)
27 A1 --- p' [ef] Upper state parity
29 A1 --- p'' [ef] Lower state parity
31- 33 I3 --- N' [0/116]? Upper state N level
35- 37 I3 --- N'' [0/116] Lower state N level
39- 49 F11.5 cm-1 Obs [1797/29550]? Observed transition position (2)
51- 60 F10.4 cm-1 Cal [-166/52350] Position calculated by PGOPHER (3)
62- 69 F8.5 cm-1 O-C ? Observed - calculated position
71- 80 F10.4 cm-1 E'' Lower state energy relative to v"=0 (4)
82- 93 E12.6 s-1 A Einstein A value
95-106 E12.6 --- f The f-value (5)
108-118 A11 --- Trans Transition description
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Note (1): In the A state, F=1 refers to Ω=0.5, and F=2 to Ω=1.5. In
the B and X states, F=1 refers to e parity, and F=2 to f parity.
Note (2): Blank if line not observed in any study.
Note (3): Using constants published in Ram et al. 2010JMoSp.263...82R 2010JMoSp.263...82R,
2006JMoSp.237..225R 2006JMoSp.237..225R
Note (4): calculated by PGOPHER and Relative to v"=0 band origin.
Note (5): The Einstein A-values are converted into f-values (oscillator
strengths) using equation (6); see section 3.
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- ESys [ABX-] Electronic system identifier (1)
5- 6 I2 --- v' [0/22] Upper state vibrational level
8- 9 I2 --- v'' [0/15] Lower state vibrational level
11- 19 E9.3 s-1 A-2Pi1/2 Einstein A value with 2Π1/2 upper
spin component
21- 29 E9.3 s-1 f-2Pi1/2 Oscillator strength with 2Π1/2 upper
spin component
31- 38 E8.3 s-1 A-2Pi3/2 ? Einstein A value with 2Π3/2 upper
spin component
40- 48 E9.3 s-1 f-2Pi3/2 ? Oscillator strength with 2Π3/2 upper
spin component
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Note (1): Where
A-X = A2Π-X2Σ+,
B-X = B2Σ+-X2Σ+, and
X-X = X2Σ+.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 02-Apr-2014