THz SPECTRA OF NHD AND ND2: FROM LABORATORY TO ASTRONOMICAL DETECTIONS

Melosso, Mattia

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https://hdl.handle.net/2142/107307 Copy

Description

Title

THz SPECTRA OF NHD AND ND2: FROM LABORATORY TO ASTRONOMICAL DETECTIONS

Author(s)

Melosso, Mattia

Contributor(s)

Puzzarini, Cristina ; Pirali, Olivier ; Martin-Drumel, Marie-Aline ; Tamassia, Filippo ; Dore, Luca ; Bizzocchi, Luca

Issue Date

23-Jun-20

Keyword(s)

Astronomy

Abstract

Amidogen (\chem{NH_2}), an asymmetric-top free radical that belongs to the nitrogen-hydrides family, plays a key intermediate role in the synthesis of interstellar ammonia. While both the main isotopologue and the $^{15}$N-substituted form of amidogen have been detected in the interstellar medium, no astronomical observations of its deuterated variants were reported to date. Recently, we have investigated the rotational spectra of all the deuterated isotopologues of amidogen radical, namely \chem{NHD}, \chem{ND_2}, $^{15}$\chem{NHD}, and $^{15}$\chem{ND_2}. The measurements have been performed using a frequency-modulation submillimeter spectrometer and a Fourier transform infrared spectrometer that exploits the bright far infrared continuum of the SOLEIL synchrotron, both instruments equipped with discharge sources to produce the radicals. Using improved predictions resulting from the new laboratory studies, \chem{NHD} and \chem{ND_2} have been searched for in the public available \emph{Herschel} spectral survey of the Class 0 protostar IRAS 16293-2422. Thanks to the observation of several hyperfine transitions between 520 and 790\,GHz, we report the first detection of both of these radicals in the interstellar medium. Deuterium fractionation of amidogen will be discussed and compared with astrochemical models.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

English

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http://hdl.handle.net/2142/107307

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