ROTATIONAL SPECTRUM AND TENTATIVE DETECTION OF DCOOCH{sub 3}-METHYL FORMATE IN ORION

Journal Article · Mon May 10 04:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/714/2/1120· OSTI ID:21448845

Margules, L; Huet, T R; Demaison, J ^[1]; Carvajal, M ^[2]; Kleiner, I ^[3]; Moellendal, H ^[4]; Tercero, B; Marcelino, N; Cernicharo, J ^[5]

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1. Laboratoire de Physique des Lasers, Atomes, et Molecules, UMR CNRS 8523, Universite Lille 1, F-59655 Villeneuve d'Ascq Cedex (France)
2. Departamento de Fisica Aplicada, Facultad de Ciencias Experimentales, Universidad de Huelva, 21071 Huelva (Spain)
3. Laboratoire Interuniversitaire des Systemes Atmospheriques, UMR CNRS 7583, Universite Paris 7 et Universite Paris 12, 61 av. Charles de Gaulle, F-94010 Creteil Cedex (France)
4. Centre for Theoretical and Computational Chemistry (CTCC), Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, NO-0315 Oslo (Norway)
5. Centro de AstrobiologIa (CSIC-INTA), Laboratory of Molecular Astrophysics, Department of Astrophysics, Ctra de Ajalvir, Km 4, 28850 Torrejon de Ardoz, Madrid (Spain)

New centimeter-wave (7-80 GHz) and submillimeter-wave (580-661 GHz) spectra of a deuterated species of methyl formate (DCOOCH{sub 3}) have been measured. Transitions with a maximum value of J = 64 and K = 36 have been assigned and fitted together with previous measurements. The internal rotation of this compound was treated using the so-called rho axis method. A total of 1703 transitions were fitted using this method. Only 24 parameters were employed in the final fit, which has an rms deviation of 94.2 kHz. The dipole moment and the nuclear quadrupole coupling constants of the deuterated specie have also been obtained. This new study has permitted a tentative detection of DCOOCH{sub 3} in Orion with the IRAM 30 m telescope based on the observation of more than 100 spectral features with low blending effects among the 400 lines expected in the observed frequency domain (for which over 300 are heavily blended with other species). These 100 transitions are above noise and confusion limited without heavy blending and cannot be assigned to any other species. Moreover, none of the strongest unblended transitions is missing. The derived source-averaged total column density for DCOOCH{sub 3} is 7.8 x 10{sup 14} cm{sup -2} and the DCOOCH{sub 3}/HCOOCH{sub 3} column density ratio varies between 0.02 and 0.06 in the different cloud components of Orion. This value is consistent with the deuteration enhancement found for other species in this cloud.

• OSTI ID: 21448845
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 714; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CHEMICAL REACTIONS
COUPLING CONSTANTS
DATA ANALYSIS
DEUTERATION
DIPOLE MOMENTS
TELESCOPES