J/A+A/587/A152 Rotational spectrum of 13C methylamine (Motiyenko+, 2016)
Millimeter and submillimeter wave spectra of 13C methylamine.
Motiyenko R.A., Margules L., Ilyushin V.V., Smirnov I.A., Alekseev E.A.,
Halfen D.T., Ziurys L.M.
<Astron. Astrophys. 587, A152 (2016)>
=2016A&A...587A.152M 2016A&A...587A.152M (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics ; Interstellar medium ; Millimetric/submm sources
Keywords: ISM: molecules - methods: laboratory: molecular -
submillimeter: ISM - molecular data - line: identification
Abstract:
Methylamine (CH3NH2) is a light molecule of astrophysical
interest, which has an intensive rotational spectrum that extends in
the submillimeter wave range and far beyond, even at temperatures
characteristic for the interstellar medium. It is likely for 13C
isotopologue of methylamine to be identified in astronomical surveys,
but there is no information available for the 13CH3NH2
millimeter and submillimeter wave spectra.
In this context, to provide reliable predictions of 13CH3NH2
spectrum in millimeter and submillimeter wave ranges, we have studied
rotational spectra of the 13C methylamine isotopologue in the
frequency range from 48 to 945GHz.
The spectrum of 13C methylamine was recorded using conventional
absorption spectrometers in Lille and Kharkov. The analysis of the
rotational spectrum of 13C methylamine in the ground vibrational
state was performed on the basis of the group- theoretical
high-barrier tunneling Hamiltonian that was developed for methylamine
by Ohashi and Hougen. The available multiple observations of the
parent methylamine species toward Sgr B2(N) at 1, 2, and 3mm using the
Submillimeter Telescope and the 12 m antenna of the Arizona Radio
Observatory were used to make a search for interstellar
13CH3NH2.
In the recorded spectra, we have assigned 2721 rotational transitions
that belong to the ground vibrational state of the 13CH3NH2.
These measurements were fitted to the Hamiltonian model that uses 75
parameters to achieve an overall weighted rms deviation of 0.73. On
the basis of these spectroscopic results, predictions of transition
frequencies in the frequency range up to 950GHz with J<50 and Ka<20
are presented. The search for interstellar 13C methylamine in
available observational data was not successful and therefore only an
upper limit of 6.5x1014cm-2 can be derived for the column density
of 13CH3NH2 toward Sgr B2(N), assuming the same source size,
temperature, linewidth, and systemic velocity as for parent
methylamine isotopic species.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 53 2721 Measured rotational transitions of 13CH3NH2
in the ground vibrational state
table4.dat 73 37985 Predicted transitions of 13C methylamine in
the ground vibrational state
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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 : Spectrum of 18O-methyl formate (HCO18OCH3) (Tercero+ 2012)
J/A+A/540/A51 : Submm spectrum of deuterated glycolaldehydes (Bouchez+, 2012)
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 : Rotational spectroscopy of diisocyanomethane (Motiyenko+, 2012
J/A+A/548/A71 : Spectroscopy and ISM detection of formamide (Motiyenko+, 2012)
J/A+A/549/A96 : The mm & sub-mm spectra of 13C-glycolaldehydes (Haykal+, 2013)
J/A+A/549/A128 : Singly deuterated isotopologues of formamide (Kutsenko+, 2013)
J/A+A/552/A117 : Mono-deuterated dimethyl ether (Richard+, 2013)
J/A+A/553/A84 : (Sub)mm spectrum of deuterated methyl cyanides (Nguyen+, 2013)
J/A+A/559/A44 : Rotational spectrum of MAAN (CH2NCH2CH) (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)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- J1 [1/43] Upper J quantum number
4- 6 I3 --- Ka1 [0/13] Upper Ka quantum number
8- 11 A4 --- G1 Upper symmetry species
12- 14 I3 --- J0 [0/43] Lower J quantum number
15- 17 I3 --- Ka0 [0/13] Lower Ka quantum number
19- 22 A4 --- G0 Lower symmetry species
25- 36 F12.3 MHz Freq [48242/944739] Observed transition frequency
39- 44 F6.3 MHz Error [0.03/0.1] Uncertainty of measurements
46- 53 F8.4 MHz O-C [-0.26/0.37] Residuals of the fit
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- J1 [1/50] Upper J quantum number
4- 6 I3 --- Ka1 [0/20] Upper Ka quantum number
8- 11 A4 --- G1 Upper symmetry species
12- 14 I3 --- F1 [0/51] Upper F quantum number
16- 18 I3 --- J0 [0/50] Lower J quantum number
19- 21 I3 --- Ka0 [0/20] Lower Ka quantum number
23- 26 A4 --- G0 Lower symmetry species
27- 29 I3 --- F0 [0/51] Lower F quantum number
31- 43 F13.4 MHz Freq [1000/949944] Calculated transition frequency
45- 51 F7.4 MHz Error [0.0005/0.9959] Calculated uncertainty
54- 60 F7.3 D2 mu2S [0/49] Calculated line strength
62- 63 I2 --- Wst Statistical weight
65- 73 F9.3 cm-1 E0 Energy of the lower state
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Acknowledgements:
Roman Motiyenko, roman.motienko(at)univ-lille1.fr
(End) Roman Motiyenko [PhLAM, Lille 1], Patricia Vannier [CDS] 11-Jan-2016