J/A+A/649/A60 Assignment & prediction of formaldoxime (CH2NOH) (Zou+, 2021)
Millimeter- and subillimeter-wave spectrum of trans-formaldoxime (CH2NOH).
Zou L., Guillemin J.-C., Motiyenko R.A., Margules L.
<Astron. Astrophys. 649, A60 (2021)>
=2021A&A...649A..60Z 2021A&A...649A..60Z (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics ; Spectroscopy
Keywords: astrochemistry - molecular data - submillimeter: ISM -
methods: laboratory: molecular
Abstract:
Among the six atoms of N-containing molecules with the formula of
CH3NO, only formamide (H2NCHO), the most stable structural isomer,
has been detected in the interstellar medium (ISM). The formaldoxime
isomer may be formed, for example, by the reaction of formaldehyde
(H2CO) or methanimine (H2CNH) and hydroxylamine (H2NOH), which
are all detected in the ISM. The lack of high accuracy millimeter- and
submillimeter-wave measurements hinders the astronomical search for
formaldoxime.
The aim of this work is to provide the direct laboratory measurement
of the millimeter- and submillimeter-wave spectrum of
trans-formaldoxime.
Formaldoxime was synthesized and its rotational spectrum was recorded
at room temperature in a glass flow cell using the millimeter- and
submillimeter-wave spectrometer in Lille. The SPFIT program in the
CALPGM suite was used to fit the spectrum.
Rotational lines of trans-formaldoxime from both the ground state and
v12=1 vibrational excited states have been measured and assigned
from 150 to 660GHz. Spectroscopic constants were derived to the tenth
order using both Watson's A and S reduction Hamiltonian.
Description:
The measure frequency line list and the prediction of formaldoxime
(CH2NOH) for the ground state and v12=1 vibrationally excited state.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 75 2232 Measured frequency CH2NOH g.s.
table5.dat 74 1307 Measured frequency CH2NOH v12=1
tablea1.dat 75 11237 *Prediction of CH2NOH pure rotational
tablea2.dat 77 46422 *Prediction of CH2NOH hyperfine
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Note on tablea1.dat, tablea2.dat: output using the CALPGM/SPCAT format.
Documentation can be found in
https://spec.jpl.nasa.gov/ftp/pub/calpgm/spinv.pdf.
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Byte-by-byte Description of file: table4.dat table5.dat
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Bytes Format Units Label Explanations
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2- 3 I2 -- J" Quantum number J of the upper state
5- 6 I2 -- Ka" Quantum number Ka of the upper state
8- 9 I2 -- Kc" Quantum number Kc of the upper state
11- 12 I2 -- vdummy" Dummy quantum number v of the upper state (1)
14- 15 I2 -- F" Quantum number F of the upper state
17- 18 I2 -- J' Quantum number J of the lower state
20- 21 I2 -- Ka' Quantum number Ka of the lower state
23- 24 I2 -- Kc' Quantum number Kc of the lower state
26- 27 I2 -- vdummy' Dummy Quantum number v of the lower state (1)
29- 30 I2 -- F' Quantum number F of the lower state
31- 42 F12.3 MHz Freq Line frequency observed
43- 47 F5.2 MHz RelInt Relative intensity for blended lines (2)
48- 56 F9.5 MHz Diff Frequency difference (obs - calc)
57- 62 F6.3 MHz Unc Line frequency uncertainty
63- 75 A13 -- Ref Reference of the observed line (3)
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Note (1): The dummy quantum number (act as a vibrational state) is
used to combine the fit of the pure rotational lines (vdummy=0) & partially
resolved hyperfine lines (vdummy=1). It does not have physical meaning, and
is removed in the prediction files tablea1.dat and tablea2.deg.
The quantum numbers are in Pickett's format, and therefore for
vdummy=0 lines F=J is always true.
Note (2): For single lines, the relative intensity is always unity (1.00).
For blended lines, the sum of the relative intensities is unity (1.00).
Note (3): Frequencies are taken from the following references:
Levine 1962 = Journal of Molecular Spectroscopy, 1962, 8, 276-284
Klesing 1990 = Zeitschrift fur Naturforschung A, 1990, 45, 817-826
Zou 2021 = this work
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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3- 13 F11.4 MHz Freq [1455.7529/999659.1104] Frequency of the
line
14- 21 F8.4 MHz e_Freq Estimated error of Freq (1)
23- 29 F7.4 [nm+2.MHz] logInt Base 10 log of the integrated intensity
31 I1 --- DOF [3] Degrees of freedom
33- 41 F9.4 cm-1 Elo Lower state energy
42- 44 I3 --- Gup Upper state degeneracy
47- 51 I5 --- Tag [45999] Species tag
52- 55 I4 --- QNFMT [1404] Quantum number (QN) format
identifier
56- 57 I2 --- J" [1/50] QN J of the upper state
58- 59 I2 --- Ka" [0/33] QN Ka of the upper state (1)
60- 61 I2 --- Kc" [0/49] QN Kc of the upper state
63 I1 --- v" [0/1] QN v of the upper state
(0 for gs & 1 for v12=1)
68- 69 I2 --- J' [0/50] QN J of the lower state
70- 71 I2 --- Ka' [0/33] QN Ka of the lower state
72- 73 I2 --- Kc' [0/50] QN Kc of the lower state
75 I1 --- v' [0/1] QN v of the lower state
(0 for gs & 1 for v12=1)
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Note (1): prediction up to J=50. Lines with Ka"≥25 or e_Freq>1.0MHz should be
treated with caution.
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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3- 13 F11.4 MHz Freq [4590.4839/999661.3492] Frequency of the
line
14- 21 F8.4 MHz e_Freq Estimated error on Freq (1)
22- 29 F8.4 [nm+2.MHz] logInt Base 10 log of the integrated intensity
31 I1 --- DOF [3] Degrees of freedom
32- 41 F10.4 cm-1 Elo Lower state energy
42- 44 I3 --- Gup Upper state degeneracy
47- 51 I5 --- Tag [45999] Species tag
52- 55 I4 --- QNFMT [1405] Quantum number (QN) format
identifier
56- 57 I2 --- J" [1/51] QN J of the upper state
58- 59 I2 --- Ka" [0/31] QN Ka of the upper state (1)
60- 61 I2 --- Kc" [0/50] QN Kc of the upper state
63 I1 --- v" [0/1] QN v of the upper state
(0 for gs & 1 for v12=1)
64- 65 I2 --- F" [0/50] QN F of the lower state
68- 69 I2 --- J' [0/51] QN J of the lower state
70- 71 I2 --- Ka' [0/31] QN Ka of the lower state
72- 73 I2 --- Kc' [0/51] QN Kc of the lower state
75 I1 --- v' [0/1] QN v of the lower state
(0 for gs & 1 for v12=1)
76- 77 I2 --- F' [0/50] QN F of the lower state
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Note (1): prediction up to J=50. Lines with Ka"≥25 or e_Freq>1.0MHz should be
treated with caution.
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Acknowledgements:
Luyao Zou, luyao.zou(at)univ-lille.fr
(End) Luyao Zou [Univ. Lille], Patricia Vannier [CDS] 16-Apr-2021