The Sub-millimeter Rotational Spectrum of Ethylene Glycol up to 890 GHz and Application to ALMA Band 10 Spectral Line Data of NGC 6334I

TL;DR

This study measures the sub-millimeter rotational spectrum of ethylene glycol up to 890 GHz, improving spectral data accuracy for astronomical observations, and applies it to ALMA data of NGC 6334I to analyze star-forming regions.

Contribution

The paper provides refined spectroscopic parameters for ethylene glycol up to 890 GHz, enabling more precise astronomical line identification and analysis.

Findings

Improved spectral catalog accuracy for ethylene glycol at high frequencies.

Successful application of laboratory data to ALMA observations of NGC 6334I.

Demonstrated importance of high-frequency laboratory spectroscopy for astronomy.

Abstract

The rotational spectrum of the most stable conformer of ethylene glycol (HO(CH$_2$)$_2$OH) has been recorded between 360-890 GHz using a frequency-modulation sub-millimeter spectrometer. The refinement and extension of the spectroscopic parameters over previous efforts provides predicted catalog frequencies for ethylene glycol with sufficient accuracy for comparison to high-frequency astronomical data. The improvement in the cataloged line positions, and the need for improved accuracy enabled by high-frequency laboratory work, is demonstrated by an analysis of ethylene glycol emission at 890 GHz in the high-mass star-forming region NGC 6334I in ALMA Band 10 observations. The need for accurate rotational spectra at sub-millimeter wavelengths/THz frequencies is discussed.