J/A+A/642/A29 Spectroscopy of CH2(CN)2 and CNCH2CN (Motiyenko+, 2020)
Millimeter- and submillimeter-wave spectroscopy of thioformamide and
interstellar search toward Sgr B2(N).
Motiyenko R.A., Belloche A, Garrod R.T., Margules L., Mueller H.S.P.,
Menten K.M., Guillemin J.-C.
<Astron. Astrophys. 642, A29 (2020)>
=2020A&A...642A..29M 2020A&A...642A..29M (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics
Keywords: astrochemistry - line: identification - radio lines: ISM -
ISM: molecules - ISM: individual objects: Sagittarius B2(N)
Abstract:
Thioformamide NH2CHS is a sulfur-bearing analog of formamide NH2CHO.
The latter was detected in the interstellar medium back in the 1970s.
Most of the sulfur-containing molecules detected in the interstellar
medium are analogs of corresponding oxygen-containing compounds.
Therefore, thioformamide is an interesting candidate for a search in
the interstellar medium.
A previous study of the rotational spectrum of thioformamide was
limited to frequencies below 70GHz and to transitions with J≤3.
The aim of this study is to provide accurate spectroscopic parameters
and rotational transition frequencies for thioformamide to enable
astronomical searches for this molecule using radio telescope arrays
at millimeter wavelengths.
The rotational spectrum of thioformamide was measured and analyzed in
the frequency range 150 to 660GHz using the Lille spectrometer. We
searched for thioformamide toward the high-mass star-forming region
Sagittarius (Sgr) B2(N) using the ReMoCA spectral line survey carried
out with the Atacama Large Millimeter/submillimeter Array (ALMA).
Accurate rigid rotor and centrifugal distortion constants were
obtained from the analysis of the ground state of parent, 34S,
13C, and 15N singly substituted isotopic species of thioformamide.
In addition, for the parent isotopolog, the lowest two excited
vibrational states, v12=1 and v9=1, were analyzed using a model
that takes Coriolis coupling into account. Thioformamide was not
detected toward the hot cores Sgr B2(N1S) and Sgr B2(N2). The
sensitive upper limits indicate that thioformamide is nearly three
orders of magnitude at least less abundant than formamide. This is
markedly different from methanethiol, which is only about two orders
of magnitude less abundant than methanol in both sources.
The different behavior shown by methanethiol versus thioformamide may
be caused by the preferential formation of the latter (on grains) at
late times and low temperatures, when CS abundances are depressed.
This reduces the thioformamide-to- formamide ratio, because the HCS
radical is not as readily available under these conditions.
Description:
Table A.1 contains assigned rotational transitions of the ground state
of thioformamide (parent isotopolog).
Table A.2 contains calculated spectral predictions of the ground state
of thioformamide at T=300K and in the frequency range up to 700GHz.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 53 1651 Assigned and fitted rotational transitions of the
ground state of thioformamide (parent isotopolog)
tablea2.dat 57 6902 Predicted rotational transitions of the v=0 state
of thioformamide at T=300K
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See also:
J/A+A/493/565 : Deuterated and 15N ethyl cyanides (Margules+, 2009)
J/A+A/538/A51 : Rotational spectrum of CH3CH(NH2)CN (Mollendal+, 2012)
J/A+A/538/A119 : 18O-methyl formate (HCO18OCH3) spectrum (Tercero+ 2013)
J/A+A/543/A46 : Submillimeter spectrum of HCOOCD2H (Coudert+, 2012)
J/A+A/543/A135 : New analysis of 13C-CH3CH2CN up to 1THz (Richard+, 2012)
J/A+A/544/A82 : Diisocyanomethane rotational spectroscopy (Motiyenko+, 2012)
J/A+A/548/A71 : Spectroscopy and ISM detection of formamide (Motiyenko+, 2012)
J/A+A/549/A96 : mm and sub-mm spectra of 13C-glycolaldehydes (Haykal+, 2013)
J/A+A/559/A44 : Rotational spectrum of MAAN (CH2NCH2CN) (Motiyenko+, 2013)
J/A+A/563/A137 : THz spectrum of methylamine (Motiyenko+, 2014)
J/A+A/568/A58 : HCOO13CH3 rotational spectrum (Haykal+, 2014)
J/A+A/579/A46 : Mono-13C acetaldehydes mm/submm wave spectra
(Margules+, 2015)
J/A+A/587/A152 : Rotational spectrum of 13C methylamine (Motiyenko+, 2016)
J/A+A/590/A93 : Doubly 13C-substituted ethyl cyanide (Margules+, 2016)
J/A+A/592/A43 : Millimeter wave spectra of carbonyl cyanide (Bteich+, 2016)
J/A+A/601/A2 : Triple 13C-substituted ethyl cyanide (Pienkina, 2017)
J/A+A/601/A49 : CH3NHCHO rotational spectroscopy (Belloche+, 2017)
J/A+A/601/A50 : Sub-millimeter spectra of 2-hydroxyacetonitrile
(Margules+, 2017)
J/A+A/610/A44 : Ethyl isocyanide submillimeter wave spectroscopy
(Margules+, 2018)
J/A+A/619/A92 : Laboratory analysis of methylketene (Bermuez+, 2018)
J/A+A/623/A162 : Spectroscopy of CH2(CN)2 and CNCH2CN (Motiyenko+, 2019)
J/A+A/624/A70 : Acetaldehyde CH2DCOH and CH3COD (Coudert+, 2019)
J/A+A/638/A3 : Cyanoketene (NC-CH=C=O) mm wave spectroscopy (Margules+, 2020)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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2- 3 I2 --- J' Upper J quantum number
5- 6 I2 --- Ka' Upper Ka quantum number
8- 9 I2 --- Kc' Upper Kc quantum number
11- 12 I2 --- J" Lower J quantum number
14- 15 I2 --- Ka" Lower Ka quantum number
17- 18 I2 --- Kc" Lower Kc quantum number
22- 32 F11.4 MHz Freq Measured transition frequency
34- 40 F7.4 MHz O-C Residual of the fit
43- 47 F5.3 MHz Unc Uncertainty of measurements
50- 53 F4.2 --- RelI ? Relative intensity for blended line components
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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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2- 3 I2 --- J' Upper J quantum number
5- 6 I2 --- Ka' Upper Ka quantum number
8- 9 I2 --- Kc' Upper Kc quantum number
11- 12 I2 --- J" Lower J quantum number
14- 15 I2 --- Ka" Lower Ka quantum number
17- 18 I2 --- Kc" Lower Kc quantum number
21- 31 F11.4 MHz Freq Calculated transition frequency
33- 39 F7.4 MHz O-C Uncertainty of pcalculated transition frequency
41- 47 F7.4 [nm+2.MHz] logInt Base 10 logarithm of the integrated intensity
49- 57 F9.4 cm-1 Elo The energy of the lower state
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Acknowledgements:
Roman Motiyenko, roman.motiyenko(at)univ-lille.fr
(End) Roman Motiyenko [PhLAM, Univ. Lille], Patricia Vannier [CDS] 18-Aug-2020