The Pure Rotational Spectrum Of The Hydroxymethyl Radical Reinvestigated To Enable Its Interstellar Detection

Chitarra, Olivia

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https://hdl.handle.net/2142/111565 Copy

Description

Title

The Pure Rotational Spectrum Of The Hydroxymethyl Radical Reinvestigated To Enable Its Interstellar Detection

Author(s)

Chitarra, Olivia

Contributor(s)

• Loison, J.-C.
• Müller, Holger S.P.
• Lattanzi, Valerio
• Spezzano, Silvia
• Pirali, Olivier
• Gans, Bérenger
• Martin-Drumel, Marie-Aline

Issue Date

2021-06-23

Keyword(s)

Astronomy

Abstract

The hydroxymethyl (CH$_2$OH) and methoxy (CH$_3$O) radicals, products of CH$_3$OH photodissociation, are considered key reactive intermediates in the interstellar medium (ISM), and their recombination with other fragments is postulated to lead to the formation of commonly observed complex organic molecules (COMs) as glycolaldehyde, ethanol, ethylene glycol, and dimethyl ether. Interestingly, despite the recent first laboratory detection of CH$_2$OH pure rotational spectrum [1] and while this isomer is the most thermodynamically stable, only CH$_3$O has so far been detected in the ISM. A plausible explanation to this lack of interstellar detection is the non-observation in the laboratory of the most intense transitions at low temperature. We have re-investigated the pure rotational spectrum of CH$_2$OH at room temperature in the millimeter-wave domain, using a frequency modulation submillimeter spectrometer, with emphasized searches for the fundamental $b$-type transitions and those intense at low temperature. The radical was produced by H abstraction from CH$_3$OH using F atoms produced by a microwave discharge. A combined fit of millimeter-wave lines from the literature and our new measurements using a rigid-rotor Hamiltonian yielded a large improvement in the spectroscopic parameters [2] values allowing now confident searches of CH$_2$OH in cold interstellar environments. \smallskip \noindent [1] C. Bermudez et al., Astronomy and Astrophysics (2017) 598, A 9 \noindent [2] O. Chitarra et al., Astronomy and Astrophysics (2020) 644, A 123

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Permalink

http://hdl.handle.net/2142/111565

DOI

10.15278/isms.2021.WJ03

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