J/ApJ/698/2114 Einstein A coeff. for ^12^C_2_D_2_ transitions (Yu+, 2009) ================================================================================ Terahertz spectroscopy and global analysis of the bending vibrations of acetylene ^12^C_2_D_2_. Yu S., Drouin B.J., Pearson J.C., Pickett H.M., Lattanzi V., Walters A. =2009ApJ...698.2114Y ================================================================================ ADC_Keywords: Atomic physics Keywords: catalogs - ISM: molecules - methods: laboratory - molecular data - techniques: spectroscopic Abstract: Two hundred and fifty-one ^12^C_2_D_2_ transitions have been measured in the 0.2-1.6THz region of its nu_5_-nu_4_ 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 ^12^C_2_D_2_ molecules were generated under room temperature by passing 120-150mTorr D_2_O vapor through calcium carbide (CaC_2_) powder. A multistate analysis was carried out for the bending vibrational modes nu_4_ and nu_5_ of ^12^C_2_D_2_, 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 ^12^C_2_D_2_ 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 ^12^C_2_D_2_ 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