Millimeter-wave spectroscopy of the ${}^{13}$CH${}_3$OD isotopic species of methyl alcohol

Abstract

The dramatic increase in sensitivity, spectral coverage and resolution of radio astronomical facilities in recent years has opened new possibilities for observation of chemical differentiation and isotopic fractionation in protostellar sources to shed light on their spatial and temporal evolution. In warm interstellar environments, methanol is an abundant species, hence spectral data for its isotopic forms are of special interest. In the present work, the millimeter-wave spectrum of the ${}^{13}$CH${}_3$OD isotopologue has been investigated over the region from 150$-$510 GHz to provide a set of transition frequencies for potential astronomical application. The focus is on two types of prominent ${}^{13}$CH${}_3$OD spectral groupings, namely the $a$-type ${}^{q}R$-branch multiplets and the $b$-type $Q$-branches. Line positions are reported for the ${}^{q}R(J)$ clusters for $J=3$ to 10 for the $v_{\mathrm{t}}=0$ and 1 torsional states, and for a number of $v_{\mathrm{t}}=0$ and 1 ${}^{r}Q(J)$ or ${}^{p}Q(J)$ line series up to $J=25$. The frequencies have been fitted to a multi-parameter torsion-rotation Hamiltonian, and upper level excitation energies have been calculated from the resulting molecular constants.

25 pages, 8 pages text and references

References in corpus (6)

• The ALMA Protostellar Interferometric Line Survey (PILS): First results from an unbiased submillimeter wavelength line survey of the Class 0 protostellar binary IRAS 16293-2422 with ALMA
• Astrochemistry During the Formation of Stars
• Questioning the spatial origin of complex organic molecules in young protostars with the CALYPSO survey
• Complex organic molecules in low-mass protostars on solar system scales -- I. Oxygen-bearing species
• Laboratory spectroscopy of 1,2-propanediol at millimeter and submillimeter wavelengths
• Millimeter Wave and Terahertz Spectra and Global Fit of Torsion-Rotation Transitions in the Ground, First and Second Excited Torsional States of 13CH3OH Methanol

Cited by in corpus (1)

• Millimetre and sub-millimetre spectroscopy of doubly deuterated acetaldehyde (CHD2CHO) and first detection towards IRAS 16293-2422