J/A+A/590/A93 Doubly 13C-substituted ethyl cyanide (Margules+, 2016)
Spectroscopic study and astronomical detection of doubly 13C-substituted
ethyl cyanide.
Margules L., Belloche A., Muller H.S.P., Motiyenko R.A., Guillemin J.-C.,
Garrod R.T., Menten K.M.
<Astron. Astrophys. 590, A93 (2016)>
=2016A&A...590A..93M 2016A&A...590A..93M (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics ; Interstellar medium ; Molecular clouds ;
Radio lines ; Spectroscopy
Keywords: molecular data - methods: laboratory: molecular -
techniques: spectroscopic - radio lines: ISM - ISM: molecules -
ISM: individual objects: Sagittarius B2(N)
Abstract:
We have performed a spectral line survey called Exploring Molecular
Complexity with ALMA (EMoCA) toward Sagittarius B2(N) between 84.1 and
114.4GHz with the Atacama Large Millimeter/submillimeter Array (ALMA)
in its Cycles 0 and 1. Line intensities of the main isotopic species
of ethyl cyanide and its singly 13C-substituted isotopomers observed
toward the hot molecular core Sagittarius B2(N2) suggest that the
doubly 13C-substituted isotopomers should also be detectable. We want
to determine the spectroscopic parameters of all three doubly
13C-substituted isotopologues of ethyl cyanide to search for them in
our ALMA data.
We investigated the laboratory rotational spectra of the three species
between 150GHz and 990GHz. We searched for emission lines produced
by these species in the ALMA spectrum of Sagittarius B2(N2). We
modeled their emission and the emission of the 12C and singly
13C-substituted isotopologues assuming local thermodynamic
equilibrium.
Description:
We identified more than 5000 rotational transitions, pertaining to
more than 3500 different transition frequencies, in the laboratory for
each of the three doubly 13C-substituted isotopomers. The quantum
numbers reach J∼115 and Ka∼35, resulting in accurate spectroscopic
parameters and accurate rest frequency calculations beyond 1000 GHz
for strong to moderately weak transitions of either isotopomer. All
three species are unambiguously detected in our ALMA data. The
12C/13C column density ratio of the isotopomers with one 13C
atom to those with two 13C atoms is about 25.
Ethyl cyanide is the second molecule after methyl cyanide for which
isotopologues containing two 13C atoms have been securely detected
in the interstellar medium. The model of our ethyl cyanide data
suggests that we should be able to detect vibrational satellites of
the main species up to at least v19=1 at 1130K and up to
v13+v21=2 at 600K for the isotopologues with one 13C atom in our
present ALMA data. Such satellites may be too weak to be identified
unambiguously for isotopologues with two 13C atoms.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
s1.dat 80 6824 CH313CH213CN: Measured frequencies, experimental
frequencies,accuracies and residuals from the fits
s2.dat 80 5496 13CH3CH213CN: Measured frequencies, experimental
frequencies,accuracies and residuals from the fits
s3.dat 80 5516 13CH313CH2CN: Measured frequencies, experimental
frequencies,accuracies and residuals from the fits
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See also:
J/A+A/493/565 : Deuterated and 15N ethyl cyanides (Margules+, 2009)
J/A+A/500/1109 : Rotational spectrum of HCOO13CH3 (Carvajal+, 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 : mm and 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 (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 : Mono13C acetaldehydes mm/submm wave spectra (Margules+ 2015)
Byte-by-byte Description of file: s1.dat s2.dat s3.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Nr Line number
5 A1 --- --- [:.]
8- 10 I3 --- J" Upper J quantum number
13- 14 I2 --- Ka" Upper Ka quantum number
16- 18 I3 --- Kc" Upper Kc quantum number
22- 24 I3 --- J' Upper N quantum number
27- 28 I2 --- Ka' Upper Ka quantum number
30- 32 I3 --- Kc' Upper Kc quantum number
38- 48 F11.4 MHz Freq Observed transition frequency
52- 57 F6.4 MHz unc Experimental uncertainty
61- 67 F7.4 MHz O-C Observed - Calculated frequencies
74- 80 E7.3 MHz Weight ? Weight for blended lines
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Acknowledgements:
Laurent Margules, laurent.margules(at)univ-lille1.fr
(End) Laurent Margules [Phlam, France], Patricia Vannier [CDS] 17-Apr-2016