J/A+A/610/A44 Ethyl isocyanide submillimeter wave spectroscopy (Margules+, 2018)
Submillimeter wave spectroscopy of ethyl isocyanide and its searches in Orion.
Margules L., Tercero B., Guillemin J.C., Motiyenko R.A., Cernicharo J.
<Astron. Astrophys. 610, A44 (2018)>
=2018A&A...610A..44M 2018A&A...610A..44M (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics
Keywords: ISM: molecules - methods: laboratory: molecular -
submillimeter: ISM - molecular data - line: identification
Abstract:
About 40 cyanide molecules have been detected in the interstellar
medium, but only 3 examples of organic isocyanide molecules were
observed in this medium. Ethyl isocyanide is one of the best
candidates for possible detection.
To date, measurements of rotational spectra are limited to 40 GHz. The
extrapolation of the prediction in the millimeter wave domain is
inaccurate and does not permit an unambiguous detection.
The rotational spectra were reinvestigated from 0.15 to 1THz. Using
the new prediction, we searched for the compound ethyl isocyanide in
Orion KL and Sgr B2.
We newly assigned 2906 transitions and fitted these new data with
those from previous studies, reaching quantum numbers up to J=103
and Ka=30. The asymmetric top Hamiltonian proposed by Watson in the
Ir representation was used for the analysis, and both reductions A and
S were tested. The search for CH3CH2NC in SgrB2 (IRAM 30m) and
Orion KL (IRAM 30m, ALMA Science Verification) result in a
non-detection; upper limits to the column density were derived.
Description:
Measured frequencies and residuals from the global fit of the
submillimeter-wave data for ethylisocyanide and files used for SPFIT.
Detailled explanations on SPFIT could be found at
https://www.astro.uni-koeln.de/cdms/pickett
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
s1.dat 74 4462 Measured frequencies and residuals from the fit
s2.lin 72 4462 .lin file, input file for SPFIT
s3.par 80 26 .par file, input file for SPFIT
s4.cat 73 17585 .cat prediction up to 990 GHz
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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)
J/A+A/591/A110 : 15NH2 amidogen radical rotational spectrum
(Margules+, 2016)
J/A+A/601/A50 : Sub-millimeter spectra of 2-hydroxyacetonitrile
(Margules+, 2017)
Byte-by-byte Description of file: s1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- J" Upper J quantum number
5- 6 I2 --- Ka" Upper Ka quantum number
7- 9 I3 --- Kc" Upper Kc quantum number
10- 12 I3 --- J' Lower J quantum number
14- 15 I2 --- Ka' Lower Ka quantum number
16- 18 I3 --- Kc' Lower Kc quantum number
39- 50 F12.5 --- Freq Observed transition frequency
56- 63 F8.5 --- O-C Observed - Calculated frequencies
68- 74 F7.5 --- unc Uncertainty of measurements
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Description of file:
File s2.lin (measured transition):
------------------------------------------------------------------------------
Bytes Format Units Label Explanations
------------------------------------------------------------------------------
1- 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
50- 59 F10.3 --- Freq Observed transition frequency
63- 67 F5.3 --- unc Uncertainty of measurements
69- 72 F4.2 --- WT relative weight of line within a blend
------------------------------------------------------------------------------
File s3.par (spectroscopic parameters):
First 3 lines for SFIPT use (see https://www.astro.uni-koeln.de/cdms/pickett)
For lines 4 to 66:
------------------------------------------------------------------------------
Bytes Format Units Label Explanations
------------------------------------------------------------------------------
9- 13 I5 --- IDPAR coding of the parameter
16- 37 E22.15 --- PAR parameter value
39- 52 E14.8 --- ERPAR parameter uncertainty
54- 64 A11 --- LABEL parameter label that is delimited by /
------------------------------------------------------------------------------
File s4.cat (spectrum prevision):
------------------------------------------------------------------------------
Bytes Format Units Label Explanations
------------------------------------------------------------------------------
3- 13 F12.4 MHz FREQ Frequency of the line
16- 21 F8.4 MHz ERR Estimated or experimental error
23- 29 F7.4 --- LGINT Base 10 logarithm of the integrated intensity
in units of nm2 MHz
31 I1 --- DR Degrees of freedom in the rotational partition
function
33- 41 F9.4 --- ELO Lower state energy in wavenumbers
42- 44 I3 --- GUP Upper state degeneracy
47- 51 I5 --- TAG Species tag or molecular identifier
53- 55 I4 --- QNFMT Identifies the format of the quantum numbers
given in the field QN
56- 57 I2 --- J" Upper J quantum number
58- 59 I2 --- Ka" Upper Ka quantum number
60- 61 I2 --- Kc" Upper Kc quantum number
68- 69 I2 --- J' Lower J quantum number
70- 71 I2 --- Ka' Lower Ka quantum number
72- 73 I2 --- Kc' Lower Kc quantum number
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Acknowledgements:
Laurent Margules, Laurent.Margules(at)univ-lille.fr
(End) Laurent Margules [Phlam, France], Patricia Vannier [CDS] 24-Jan-2018