Abstract-The First Astrophysical Detection, Terahertz Spectrum, and Database for the Monodeuterated Species of Methyl Formate HCOOCH2D

http://iopscience.iop.org/0004-637X/779/2/119/pdf/0004-637X_779_2_119.pdf
L. H. Coudert¹, B. J. Drouin², B. Tercero³, J. Cernicharo³, J.-C. Guillemin⁴, R. A. Motiyenko⁵, and L. Margulès⁵

laurent.coudert@lisa.u-pec.fr
¹ LISA, UMR 7583 CNRS-Universités Paris Est Créteil et Paris Diderot, 61 Avenue du Général de Gaulle, F-94010 Créteil, France
² Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
³ Centro de Astrobiologia (CSIC-INTA), Laboratory of Molecular Astrophysics, Department of Astrophysics, Ctra de Ajalvir, Km 4, E-28850 Torrejón de Ardoz, Madrid, Spain
⁴ Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-ENSCR, 11 Allée de Beaulieu, CS 50837, F-35708 Rennes Cedex 7, France
⁵ Laboratoire de Physique des Lasers, Atomes et Molécules, UMR 8523 CNRS-Université Lille I, Bât. P5, F-59655 Villeneuve d'Ascq Cedex, France

L. H. Coudert et al. 2013 ApJ 779 119. doi:10.1088/0004-637X/779/2/119
Received 10 July 2013, accepted for publication 13 October 2013. Published 2 December 2013.
© 2013. The American Astronomical Society. All rights reserved.

Based on new measurements carried out in the laboratory from 0.77 to 1.2 THz and on a line-frequency analysis of these new data, along with previously published data, we build a line list for HCOOCH₂D that leads to its first detection in the Orion KL nebula. The observed lines, both in space and in the laboratory, involve the cis D-in-plane and trans D-out-of-plane conformations of HCOOCH₂D and the two tunneling states arising from the large-amplitude motion connecting the two trans configurations. The model used in the line position calculation accounts for both cis and trans conformations, as well as the large-amplitude motion.