J/ApJ/698/2114 Einstein A coeff. for 12C2D2 transitions (Yu+, 2009)
Terahertz spectroscopy and global analysis of the bending vibrations of
acetylene 12C2D2.
Yu S., Drouin B.J., Pearson J.C., Pickett H.M., Lattanzi V., Walters A.
<Astrophys. J., 698, 2114-2120 (2009)>
=2009ApJ...698.2114Y 2009ApJ...698.2114Y
ADC_Keywords: Atomic physics
Keywords: catalogs - ISM: molecules - methods: laboratory - molecular data -
techniques: spectroscopic
Abstract:
Two hundred and fifty-one 12C2D2 transitions have been measured
in the 0.2-1.6THz region of its nu5-nu4 difference band and 202 of
them were observed for the first time. The accuracy of these
measurements is estimated to be ranging from 50kHz to 100kHz. The
12C2D2 molecules were generated under room temperature by
passing 120-150mTorr D2O vapor through calcium carbide (CaC2)
powder. A multistate analysis was carried out for the bending
vibrational modes nu4 and nu5 of 12C2D2, which includes the
lines observed in this work and prior microwave, far-infrared and
infrared data on the pure bending levels. Significantly improved
molecular parameters were obtained for 12C2D2 by adding the new
measurements to the old data set, which had only 10 lines with
microwave measurement precision. New frequency and intensity
predictions have been made based on the obtained molecular parameters.
The more precise measurements and new predictions reported here will
support the analyses of astronomical observations by the future
high-resolution spectroscopy telescopes such as Herschel, SOFIA, and
ALMA, which will work in the terahertz spectral region.
File Summary:
--------------------------------------------------------------------------------
FileName recl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tables5.dat 104 6554 Einstein A coefficients for 12C2D2 transitions
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tables5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 F13.4 MHz Freq Frequency of the line
15- 21 F7.4 MHz e_Freq Estimated or experimental error on Freq
23- 29 F7.3 [nm2.MHz] logInt Base 10 logarithm of the
integrated intensity at 300K
31 I1 --- DR [2] Degree of freedom in the rotation
partition function
33- 41 F9.4 cm-1 Elo Lower state energy
43- 51 F9.4 cm-1 Eup upper state energy
53- 55 I3 --- gup Upper state degeneracy
57- 65 E9.4 --- Fup Fraction part of the upper state
67- 72 I6 --- Tag Molecular identifier (-28009 or 28009)
74- 77 I4 --- QNFMT [1303] Format of the quantum number
79- 80 I2 --- J' [0/66] Upper state quantum number J'
82- 83 I2 --- K' [-3/3] Upper state quantum number K'
85- 86 I2 --- V' [1/14] Upper state quantum number V'
88- 89 I2 --- J" [0/66] Lower state quantum number J"
91- 92 I2 --- K" [-2/2] Lower state quantum number K"
94 I1 --- V" [0/9] Lower state quantum number V"
96-104 E9.4 s-1 A Einstein A coefficient
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 03-Dec-2011