The rotation-torsion spectrum of CD2HOH

Coudert, L. H.; Motiyenko, R. A.; Margulès, L.; Kwabia, Fridolin

doi:10.1016/j.jms.2021.111515

Cited by 6 publications

(10 citation statements)

References 32 publications

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“…Those involving the second and third torsional states were already reported in Ndao et al (2016). The assignment of the perturbed transitions with 0 ≤ K < 3 within the three first torsional state was successfully carried out by Coudert et al (2021) thanks to an improved version of the theoretical approach of Ndao et al (2016). For the same torsional torsional states, new parallel and perpendicular transitions were assigned up to K = 12 and J = 40.…”

Section: Spectroscopy Of Chd 2 Ohmentioning

confidence: 88%

“…This paper presents a new precise spectroscopic dataset for di-deuterated methanol, CHD 2 OH, based on the global line position analysis of Coudert et al (2021) together with an observational search toward the low-mass protostellar system IRAS 16293-2422 in the data from the Atacama Large Millimeter/submillimeter Array (ALMA) Protostellar Interferometric Line Survey (PILS; Jørgensen et al 2016). Until now, CHD 2 OH has been the missing link in the chain of methanol deuteration.…”

Section: Discussionmentioning

confidence: 99%

“…The results of the global line position analysis of Coudert et al (2021) were used to build a spectroscopic database for CHD 2 OH. All rotation-torsion lines within and between the first three torsional states, 0 ≤ v t ≤ 2, were computed up to J = 26.…”

Section: Spectroscopy Of Chd 2 Ohmentioning

confidence: 99%

“…Columns 7 and 8 contain the species tag (TAG) and format number (QNFMT), respectively. Finally, columns 9 to 12 (13-16) give the assignment of the upper (lower) level in terms of the rotational quantum numbers J, K, p introduced by Coudert et al (2021) and the torsional quantum number v t . A minimum value of 10 kHz was selected for the calculated error (ERR).…”

Section: Spectroscopy Of Chd 2 Ohmentioning

confidence: 99%

“…Only transitions with a discrepancy larger than 0.5 MHz appear. Transitions are assigned using the rotational quantum numbers J, K, p (Coudert et al 2021) and the torsional label (Su & Quade 1989b) of the upper and lower levels. (a) The frequency calculated in this work is given in MHz.…”

Section: Spectral Analysismentioning

confidence: 99%

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Successive deuteration in low-mass star-forming regions: The case of D₂-methanol (CHD₂OH) in IRAS 16293-2422

Drozdovskaya

Coudert

Margulès

et al. 2022

A&A

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Context. Di-deuterated molecules are observed in the earliest stages of star formation at abundances of a few percent relative to their nondeuterated isotopologs, which is unexpected considering the scarcity of deuterium in the interstellar medium. With sensitive observations leading to the detection of a steadily increasing number of di-deuterated species, it is becoming possible to explore successive deuteration chains. Aims. The accurate quantification of the column density of di-deuterated methanol is a key piece of the puzzle that is missing in the otherwise thoroughly constrained family of D-bearing methanol in the deeply embedded low-mass protostellar system and astrochemical template source IRAS 16293-2422. A spectroscopic dataset for astrophysical purposes was built for CHD2OH and made publicly available to facilitate the accurate characterization of this species in astrochemical surveys. Methods. The newly computed line list and partition function were used to search for CHD2OH toward IRAS 16293-2422 A and B in data from the Atacama Large Millimeter/submillimeter Array (ALMA) Protostellar Interferometric Line Survey (PILS). Only nonblended, optically thin lines of CHD2OH were used for the synthetic spectral fitting. Results. The constructed spectroscopic database contains line frequencies and strengths for 7417 transitions in the 0–500 GHz frequency range. ALMA-PILS observations in the 329–363 GHz range were used to identify 105 unique, nonblended, optically thin line frequencies of CHD2OH for synthetic spectral fitting. The derived excitation temperatures and column densities yield high D/H ratios of CHD2OH in IRAS 16293-2422 A and B of 7.5 ± 1.1% and 7.7 ± 1.2%, respectively. Conclusions. Deuteration in IRAS 16293-2422 is not higher than in other low-mass star-forming regions (L483, SVS13-A, NGC 1333-IRAS2A, -IRAS4A, and -IRAS4B). Di-deuterated molecules consistently have higher D/H ratios than their mono-deuterated counterparts in all low-mass protostars, which may be a natural consequence of H–D substitution reactions as seen in laboratory experiments. The Solar System’s natal cloud, as traced by comet 67P/Churyumov–Gerasimenko, may have had a lower initial abundance of D, been warmer than the cloud of IRAS 16293-2422, or been partially reprocessed. In combination with accurate spectroscopy, a careful spectral analysis, and the consideration of the underlying assumptions, successive deuteration is a robust window on the physicochemical provenance of star-forming systems.

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Section: Spectroscopy Of Chd 2 Ohmentioning

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Section: Spectroscopy Of Chd 2 Ohmentioning

confidence: 99%

Section: Spectroscopy Of Chd 2 Ohmentioning

confidence: 99%

Section: Spectral Analysismentioning

confidence: 99%

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Successive deuteration in low-mass star-forming regions: The case of D₂-methanol (CHD₂OH) in IRAS 16293-2422

Drozdovskaya

Coudert

Margulès

et al. 2022

A&A

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Severe perturbation and observation of forbidden transitions in asymmetrically deuterated methanol (CHD2OH) and atlas of very accurate torsional rotational spectrum obtained using Synchrotron radiation

Mukhopadhyay,

Billinghurst

2024

Infrared Physics & Technology

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Methanol deuteration in high-mass protostars

Gelder

Jaspers

Nazari

et al. 2022

A&A

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Context. The deuteration of molecules forming in the ices such as methanol (CH 3 OH) is sensitive to the physical conditions during their formation in dense cold clouds and can be probed through observations of deuterated methanol in hot cores. Aims. The aim is to determine the D/H ratio of methanol for a large sample of 99 high-mass protostars and to link this to the physical conditions during the formation of methanol in the prestellar phases. Methods. Observations with the Atacama Large Millimeter/submillimeter Array (ALMA) containing transitions of CH 3 OH, CH 2 DOH, CHD 2 OH, 13 CH 3 OH, and CH 18 3 OH are investigated. The column densities of CH 2 DOH, CHD 2 OH, and CH 3 OH are determined for all sources, where the column density of CH 3 OH is derived from optically thin 13 C and 18 O isotopologues. Consequently, the D/H ratio of methanol is derived taking statistical effects into account. Results. Singly deuterated methanol (CH 2 DOH) is detected at the 3σ level toward 25 of the 99 sources in our sample of the highmass protostars. Including upper limits, the (D/H) CH 3 OH ratio inferred from N CH 2 DOH /N CH 3 OH was derived for 38 of the 99 sources and varies between ∼ 10 −3 − 10 −2 . Including other high-mass hot cores from the literature, the mean methanol D/H ratio is 1.1 ± 0.7 × 10 −3 . This is more than one order of magnitude lower than what is seen for low-mass protostellar systems (2.2 ± 1.2 × 10 −2 ). Doubly deuterated methanol (CHD 2 OH) is detected at the 3σ level toward 11 of the 99 sources. Including upper limits for 15 sources, the (D/H) CH 2 DOH ratios derived from N CHD 2 OH /N CH 2 DOH are more than two orders of magnitude higher than (D/H) CH 3 OH with an average of 2.0 ± 0.8 × 10 −1 which is similar to what is found for low-mass sources. Comparison with literature GRAINOBLE models suggests that the high-mass prestellar phases are either warm (> 20 K) or live shorter than the free-fall timescale. In contrast, for low-mass protostars, both a low temperature of < 15 K and a prestellar phase timescale longer than the free-fall timescale are necessary. Conclusions. The (D/H) CH 3 OH ratio drops by more than an order of magnitude between low-mass and high-mass protostars due to either a higher temperature during the prestellar phases or shorter prestellar phases. However, successive deuteration toward CHD 2 OH seems equally effective between low-mass and high-mass systems.

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The rotation-torsion spectrum of CD2HOH

Cited by 6 publications

References 32 publications

Successive deuteration in low-mass star-forming regions: The case of D₂-methanol (CHD₂OH) in IRAS 16293-2422

Successive deuteration in low-mass star-forming regions: The case of D₂-methanol (CHD₂OH) in IRAS 16293-2422

Severe perturbation and observation of forbidden transitions in asymmetrically deuterated methanol (CHD2OH) and atlas of very accurate torsional rotational spectrum obtained using Synchrotron radiation

Methanol deuteration in high-mass protostars

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The rotation-torsion spectrum of CD2HOH

Cited by 6 publications

References 32 publications

Successive deuteration in low-mass star-forming regions: The case of D2-methanol (CHD2OH) in IRAS 16293-2422

Successive deuteration in low-mass star-forming regions: The case of D2-methanol (CHD2OH) in IRAS 16293-2422

Severe perturbation and observation of forbidden transitions in asymmetrically deuterated methanol (CHD2OH) and atlas of very accurate torsional rotational spectrum obtained using Synchrotron radiation

Methanol deuteration in high-mass protostars

Contact Info

Product

Resources

About

Successive deuteration in low-mass star-forming regions: The case of D₂-methanol (CHD₂OH) in IRAS 16293-2422

Successive deuteration in low-mass star-forming regions: The case of D₂-methanol (CHD₂OH) in IRAS 16293-2422