J/ApJS/181/433 Spectrum of ethyl formate (Medvedev+, 2009)
The millimeter- and submillimeter-wave spectrum of the trans and gauche
conformers of ethyl formate.
Medvedev I.R., De Lucia F.C., Herbst E.
<Astrophys. J. Suppl. Ser., 181, 433-438 (2009)>
=2009ApJS..181..433M 2009ApJS..181..433M
ADC_Keywords: Atomic physics ; Spectra, millimetric/submm
Keywords: catalogs - submillimeter - techniques: spectroscopic
Abstract:
Since methyl formate (O=CH-O-CH3) is found to have a high abundance
in Hot molecular cores and other types of clouds in the galactic
center, it is reasonable to search among such sources for detectable
abundances of the more complex analog ethyl formate (O=CH-OOC2H5).
Following a previous study of the millimeter-wave spectrum of ethyl
formate, we have extended the analysis of the vibrational ground state
of the trans and gauche conformers of ethyl formate into the
submillimeter-wave range. Over 2200 new spectral lines have been
measured and analyzed at frequencies up to 380GHz. Fitting the data
for each conformer to a Watson A-reduced asymmetric-top Hamiltonian
has allowed us to predict the frequencies and intensities of many more
transitions through 380GHz.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 55 1159 Assigned and fitted transition frequencies of
the trans conformer of ethyl formate in the
vibrational ground state
table2.dat 55 1088 Assigned and fitted transition frequencies of
the gauche conformer of ethyl formate in the
vibrational ground state
table5.dat 68 7614 Predicted transition frequencies of the trans
conformer of ethyl formate in the vibrational
ground state
table6.dat 68 10597 Predicted transition frequencies of the gauche
conformer of ethyl formate in the vibrational
ground state
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Byte-by-byte Description of file: table[12].dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- J' Upper J quantum number (G1)
4- 5 I2 --- Ka' Upper Ka quantum number (G1)
7- 8 I2 --- Kc' Upper Kc quantum number (G1)
10- 11 I2 --- J" Lower J quantum number (G1)
13- 14 I2 --- Ka" Lower Ka quantum number (G1)
16- 17 I2 --- Kc" Lower Kc quantum number (G1)
20- 30 F11.4 MHz Freq Experimental frequency of the transition
32 A1 --- f_Freq [B] Flag for blended transition (1)
35- 42 F8.4 MHz O-C Observed minus calculated value
44- 51 F8.2 MHz e_Freq Estimated experimental uncertainty in Freq
53- 55 A3 --- r_Freq Source of measurement (2)
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Note (1): B indicates components of an unresolved blend of lines with
different quantum numbers, in which case the mean of their respective
frequencies is fitted.
Note (2): Source as follows:
1 = Riveros, J. M. and Wilson, Jr., E. B. 1967, Journal of Chemical Physics,
46, 4605 (1967JChPh..46.4605R 1967JChPh..46.4605R)
2 = This work
3 = Demaison, J., D. Boucher, Burie, J. Burie and Dubrulle, A., 1984,
Zeitschrift fuer Naturforschung,39A, 560 (1984ZNatA..39..560D 1984ZNatA..39..560D)
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Byte-by-byte Description of file: table[56].dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- J' Upper J quantum number (G1)
5- 7 I3 --- Ka' Upper Ka quantum number (G1)
9- 11 I3 --- Kc' Upper Kc quantum number (G1)
13- 15 I3 --- J" Lower J quantum number (G1)
17- 19 I3 --- Ka" Lower Ka quantum number (G1)
21- 23 I3 --- Kc" Lower Kc quantum number (G1)
25- 36 F12.4 MHz Freq Frequency of the transition
38- 45 F8.4 MHz e_Freq Estimated uncertainty in Freq,
1σ standard deviation
47- 54 F8.3 D2 LineStr Line strength times µG2 (1)
56 A1 --- G-DMC [abc] Dipole moment component label (2)
59- 66 F8.3 K Eup/k Upper state energy (divided by Boltzmann's)
68 A1 --- n_Freq [e] e: Experimentally measured transition
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Note (1): Line strengths for a-, b- or c-type transitions multiplied by the
square of the dipole moment component in Debye along the a, b or c
principal axis, as precised in G-DMC label.
Note (2): Dipole moment component label as follows:
a = Determined for µa=1.85D for table5, µa=1.44D for table6
b = Determined for µb=0.69D for table5, µb=1.05D for table6
c = Determined for µc=0.25D for table6
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Global Notes:
Note (G1): The rotational levels of an asymmetric top are characterized by
the overall rotational quantum number J and two pseudo-quantum numbers
Ka and Kc, which represent the projections of the total angular
momentum on the symmetry axes of the prolate and oblate symmetric
top limits (Gordy & Cook, 1984, Microwave Molecular Spectra
(New York: Wiley)).
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 28-Oct-2009