J/A+A/619/A92       Laboratory analysis of methylketene         (Bermuez+, 2018)

The millimeter-wave spectrum of methyl ketene and its astronomical search. Bermuez C., Tercero B., Motiyenko R.A., Margules L., Cernicharo J., Ellinger Y., Guillemin J.-C. <Astron. Astrophys. 619, A92 (2018)> =2018A&A...619A..92B 2018A&A...619A..92B (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics ; Interstellar medium Keywords: ISM: molecules - methods: laboratory: molecular - submillimeter: ISM - molecular data - line: identification Abstract: The analysis of isomeric species of a compound observed in the interstellar medium is a useful tool to understand the chemistry of complex organic molecules. It could, likewise, assist to detect new species. Our goal consists on analyzing one of the two most stable species of the C3H4O family, methyl ketene, whose actual rotational parameters are not precise enough to allow its detection in the ISM. The obtained parameters will be used to search for it in the high-mass star-forming regions Orion KL and Sagittarius B2 as well as in the cold dark clouds TMC-1 in Taurus Molecular Cloud and Barnard 1 (B1-b). Description: Millimeterwave room-temperature rotational spectrum of methyl ketene was recorded from 50 to 330∼GHz. The internal rotation analysis of its ground state and first torsional excited state was performed with the rho-axis-method employing RAM36 program. More than 3000 transitions of the rotational spectrum of the ground state (Kamax=18) and first torsional excited state Kamax=13 of methyl ketene were fitted using a Hamiltonian that contains 41 parameters with RMS of 41kHz. Column density limits were calculated but no lines were detected in the ISM belonging to methyl ketene. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table3.dat 74 3253 Transitions included in the fit of v18=0,1 state table4.dat 98 27514 Transitions of v18=0,1 states predicted from fit -------------------------------------------------------------------------------- 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+ 20 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/ApJ/779/119 : HCOOCH2D detection in Orion KL (Coudert+, 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 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/A49 : CH3NHCHO rotational spectroscopy (Belloche+, 2017) Byte-by-byte Description of file: table3.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 3- 4 I2 --- m0 Quantum number m for upper level 7- 8 I2 --- J0 Quantum number J for upper level 11- 12 I2 --- Ka0 Quantum number Ka for upper level 15- 16 I2 --- Kc0 Quantum number Kc for upper level 21- 22 I2 --- m1 Quantum number m for lower level 25- 26 I2 --- J1 Quantum number J for lower level 29- 30 I2 --- Ka1 Quantum number Ka for lower level 33- 34 I2 --- Kc1 Quantum number Kc for lower level 39- 49 F11.4 MHz Freq Measured frequency 56- 61 F6.4 MHz unc Uncertainty associated to frequency 69- 74 F6.4 MHz O-C Difference between calculated and observed frequency -------------------------------------------------------------------------------- Byte-by-byte Description of file: table4.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 3- 4 I2 --- m0 Quantum number m for upper level 7- 8 I2 --- J0 Quantum number J for upper level 11- 12 I2 --- Ka0 Quantum number Ka for upper level 15- 16 I2 --- Kc0 Quantum number Kc for upper level 21- 22 I2 --- m1 Quantum number m for lower level 25- 26 I2 --- J1 Quantum number J for lower level 29- 30 I2 --- Ka1 Quantum number Ka for lower level 33- 34 I2 --- Kc1 Quantum number Kc for lower level 39- 49 F11.4 MHz Freq Calculated frequency 55- 62 F8.4 MHz unc ? Uncertainty associated to calculation 67- 74 F8.4 D+2 Smu2 Transition strength: mu2*S 79- 87 E9.4 --- Aup Einstein coefficients 90- 98 F9.4 cm-1 Elow Energy of the lower state level -------------------------------------------------------------------------------- Acknowledgements: Celina Bernudez, celina.bermudez(at)univ-lille1.fr
(End) Patricia Vannier [CDS] 31-Jul-2018
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