L Kolesniková1, J L Alonso1, C Bermúdez1, E R Alonso1, B Tercero2, J Cernicharo2, J-C Guillemin3. 1. Grupo de Espectroscopía Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain. 2. Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Spain. 3. Institut des Sciences Chimiques de Rennes, École Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7, France.
Abstract
AIMS: The recent discovery of methyl isocyanate (CH3NCO) in Sgr B2(N) and Orion KL makes methyl cyanate (CH3OCN) a potential molecule in the interstellar medium. The aim of this work is to fulfill the first requirement for its unequivocal identification in space, i.e. the availability of transition frequencies with high accuracy. METHODS: The room-temperature rotational spectrum of methyl cyanate was recorded in the millimeter wave domain from 130 to 350 GHz. All rotational transitions revealed A-E splitting owing to methyl internal rotation and were globally analyzed using the ERHAM program. RESULTS: The data set for the ground torsional state of methyl cyanate exceeds 700 transitions within J″ = 10 - 35 and [Formula: see text] and newly derived spectroscopic constants reproduce the spectrum close to the experimental uncertainty. Spectral features of methyl cyanate were then searched for in Orion KL, Sgr B2(N), B1-b, and TMC-1 molecular clouds. Upper limits to the column density of methyl cyanate are provided.
AIMS: The recent discovery of methyl isocyanate (CH3NCO) in Sgr B2(N) and Orion KL makes methyl cyanate (CH3OCN) a potential molecule in the interstellar medium. The aim of this work is to fulfill the first requirement for its unequivocal identification in space, i.e. the availability of transition frequencies with high accuracy. METHODS: The room-temperature rotational spectrum of methyl cyanate was recorded in the millimeter wave domain from 130 to 350 GHz. All rotational transitions revealed A-E splitting owing to methyl internal rotation and were globally analyzed using the ERHAM program. RESULTS: The data set for the ground torsional state of methyl cyanate exceeds 700 transitions within J″ = 10 - 35 and [Formula: see text] and newly derived spectroscopic constants reproduce the spectrum close to the experimental uncertainty. Spectral features of methyl cyanate were then searched for in Orion KL, Sgr B2(N), B1-b, and TMC-1 molecular clouds. Upper limits to the column density of methyl cyanate are provided.
Authors: Fred Goesmann; Helmut Rosenbauer; Jan Hendrik Bredehöft; Michel Cabane; Pascale Ehrenfreund; Thomas Gautier; Chaitanya Giri; Harald Krüger; Léna Le Roy; Alexandra J MacDermott; Susan McKenna-Lawlor; Uwe J Meierhenrich; Guillermo M Muñoz Caro; Francois Raulin; Reinhard Roll; Andrew Steele; Harald Steininger; Robert Sternberg; Cyril Szopa; Wolfram Thiemann; Stephan Ulamec Journal: Science Date: 2015-07-31 Impact factor: 47.728