LEVERAGING DOUBLE-RESONANCE SPECTROSCOPY TO UNDERSTAND TRANS-GLYCIALDEHYDE AND 17 OF ITS VIBRATIONALLY EXCITED STATES

Bonah, Luis

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Description

Title

LEVERAGING DOUBLE-RESONANCE SPECTROSCOPY TO UNDERSTAND TRANS-GLYCIALDEHYDE AND 17 OF ITS VIBRATIONALLY EXCITED STATES

Author(s)

Bonah, Luis

Contributor(s)

• Schlemmer, Stephan
• Guillemin, J.-C.
• Müller, Holger S. P.
• Thorwirth, Sven

Issue Date

2023-06-22

Keyword(s)

Vibrational structure/frequencies

Abstract

Rotational spectra of vibrationally excited species are important tracers for the temperature structure of astronomical objects such as high-mass star-forming regions and are also assumed to be the reason for many yet unassigned spectroscopic features observed in line-rich sources. Thus, they bear high astronomical interest but are so far largely unexplored. Here, the ground state and 17 vibrationally excited states of the trans conformer of glycialdehyde (C₃H₄O₂) are examined. The low-lying torsional motion of the aldehyde group trans to the oxirane ring at about 140 ± 10 cm−¹ and the three non-zero dipole moment components lead to a dense and complicated mm-wave spectrum. High-resolution broadband spectra were recorded in the frequency ranges of 75−170 GHz and 500−750 GHz with an in-house synthesized sample. The broadband spectra alone were not sufficient for identifying the weak rotational transitions of vibrationally excited states high in energy and therefore were supported by double-resonance double-modulation (DM- DR) measurements for which an updated experimental implementation was used.ᵃ DM-DR measurements are a convenient method to derive the relationships of transitions by identifying transitions that share a common energy level. This greatly simplified the assignment of series of perturbed or weak vibrational satellites. Candidates were identified either by visual inspection in Loomis-Wood plots in our LLWP softwareᵇ or automated with peaklists. The preliminary results of the analysis including the interaction analysis of selected states will be presented.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Handle URL

https://hdl.handle.net/2142/122483

DOI

https://doi.org/10.15278/isms.2023.6810

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