J/A+A/651/A120 CH3OCHD2 experimental frequencies (Richard+, 2021)
Torsional-rotational spectrum of doubly-deuterated dimethyl ether
(CH3OCHD2). First ALMA detection in the interstellar medium.
Richard C., Jorgensen J.K., Margules L., Motiyenko R.A., Guillemin J.C.,
Groner P.
<Astron. Astrophys. 651, A120 (2021)>
=2021A&A...651A.120R 2021A&A...651A.120R (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics
Keywords: molecular data - submillimeter: ISM - ISM: molecules - astrochemistry
Abstract:
In 2013, we have published the first rotational analysis and detection
of mono-deuterated dimethyl ether in the solar-type protostar IRAS
16293-2422 with the IRAM 30m telescope. Dimethyl ether is one of the
most abundant complex organic molecules (COMs) in star-forming regions
and their D-to-H (D/H) ratios is important to understand its chemistry
and trace the source history. We present the first analysis of
doubly-deuterated dimethyl ether (methoxy-d2-methane,
1,1-dideuteromethylether) in its ground- vibrational state, based on
an effective Hamiltonian for an asymmetric rotor molecules with
internal rotors. The analysis covers the frequency range
0.15-1.5THz. The laboratory rotational spectrum of this species was
measured between 150 and 1500GHz with the Lille's submillimeter
spectrometer. For the astronomical detection, we used the Atacama
Large Millimeter/submillimeter Array (ALMA) observations from the
Protostellar Interferometric Line Survey, PILS. New sets of
spectroscopic parameters have been determined by a least squares fit
with the ERHAM code for both symmetric and asymmetric conformers. As
for the mono-deuterated species, these parameters have permitted the
first identification in space of both conformers of a
doubly-deuterated dimethyl ether via detection near the B component of
the Class 0 protostar IRAS 16293-2422.
Description:
The tables present the experimental frequencies of rotational
transitions for the symmetric and asymmetric conformers of
doubly-deuterated dimethylether up to 1.5THz as well as the predicted
frequencies up to 1.5THz.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 45 3195 Experimental frequencies measured in laboratory
up to 1.5THz for the symmetric conformer
tablea2.dat 45 3765 Experimental frequencies measured in laboratory
up to 1.5THz for the asymmetric conformer
tableb1.dat 56 14023 Predicted transition frequencies of
doubly-deuterated DME in the ground-vibrational
state for the symmetric conformer
tableb2.dat 56 15084 Predicted transition frequencies of
doubly-deuterated DME in the ground-vibrational
state for the asymmetric conformer
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Byte-by-byte Description of file: tablea1.dat tablea2.dat
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Bytes Format Units Label Explanations
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1 I1 --- sig [0/1] Symmetry number σ: 0(A), 1(E)
3- 4 I2 --- J0 J value of the lower state
6- 7 I2 --- Ka0 Ka value of the lower state
9- 10 I2 --- Kc0 Kc value of the lower state
12- 13 I2 --- J1 J value of the upper state
15- 16 I2 --- Ka1 Ka value of the upper state
18- 19 I2 --- Kc1 Kc value of the upper state
21- 31 F11.3 --- Freq Measured frequency
33- 37 F5.3 --- Acc Accuracy of the measure
39- 45 F7.4 --- O-C Observed-calculated frequency
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Byte-by-byte Description of file: tableb1.dat tableb2.dat
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Bytes Format Units Label Explanations
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1 I1 --- sig [0/1] Symmetry number σ: 0(A), 1(E)
3- 4 I2 --- J0 J value of the lower state
6- 7 I2 --- Ka0 Ka value of the lower state
9- 10 I2 --- Kc0 Kc value of the lower state
12- 13 I2 --- J1 J value of the upper state
15- 16 I2 --- Ka1 Ka value of the upper state
18- 19 I2 --- Kc1 Kc value of the upper state
21- 31 F11.3 --- Freq Predicted frequency
33- 37 F5.3 --- e_Freq Uncertainty of the prediction
39 I1 --- Spin [4] Spin weight
41- 47 F7.4 --- S Line strength for the dipole µb component
49- 56 F8.3 --- E' Value of the upper energy level
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Acknowledgements:
Cyril Richard, cyril.richard(at)univ.bourgogne.fr
(End) Cyril Richard [ICB, Dijon], Patricia Vannier [CDS] 23-Jun-2021