Millimeter and submillimeter wave spectra of<sup>13</sup>C-glycolaldehydes

Haykal, I.; Motiyenko, R. A.; Margulès, L.; Huet, T. R.

doi:10.1051/0004-6361/201220632

Cited by 18 publications

(14 citation statements)

References 15 publications

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“…Similar to the approach above we generate synthetic spectra and match those with the lines predicted to be the brightest in the spectra. The spectroscopy for the isotopologues is available through the CDMS database: for the two 13 C-isotopologues of glycolaldehyde, 13 CH 2 OHCHO and CH 2 OH 13 CHO, the data are based on measurements by Haykal et al (2013), while those for the three deuterated isotopologues, CHDOHCHO, CH 2 ODCHO and CH 2 OHCDO, are based on Bouchez et al (2012). The partition function for the isotopologues listed by the CDMS do not include the corrections for the vibrational contributions.…”

Section: Isotopologues Of Glycolaldehydementioning

confidence: 99%

The ALMA Protostellar Interferometric Line Survey (PILS)

Jørgensen

Wiel

Coutens

et al. 2016

A&A

380

582

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Context. The inner regions of the envelopes surrounding young protostars are characterised by a complex chemistry, with prebiotic molecules present on the scales where protoplanetary disks eventually may form. The Atacama Large Millimeter/submillimeter Array (ALMA) provides an unprecedented view of these regions zooming in on Solar System scales of nearby protostars and mapping the emission from rare species. Aims. The goal is to introduce a systematic survey, "Protostellar Interferometric Line Survey (PILS)", of the chemical complexity of one of the nearby astrochemical templates, the Class 0 protostellar binary IRAS 16293−2422, using ALMA, to understand the origin of the complex molecules formed in its vicinity. In addition to presenting the overall survey, the analysis in this paper focuses on new results for the prebiotic molecule glycolaldehyde, its isomers and rarer isotopologues and other related molecules.Methods. An unbiased spectral survey of IRAS 16293−2422 covering the full frequency range from 329 to 363 GHz (0.8 mm) has been obtained with ALMA, in addition to a few targeted observations at 3.0 and 1.3 mm. The data consist of full maps of the protostellar binary system with an angular resolution of 0.5 (60 AU diameter), a spectral resolution of 0.2 km s −1 and a sensitivity of 4-5 mJy beam −1 km s −1 -approximately two orders of magnitude better than any previous studies. Results. More than 10,000 features are detected toward one component in the protostellar binary, corresponding to an average line density of approximately one line per 3 km s −1 . Glycolaldehyde, its isomers, methyl formate and acetic acid, and its reduced alcohol, ethylene glycol, are clearly detected and their emission well-modeled with an excitation temperature of 300 K. For ethylene glycol both lowest state conformers, aGg and gGg , are detected, the latter for the first time in the ISM. The abundance of glycolaldehyde is comparable to or slightly larger than that of ethylene glycol. In comparison to the Galactic Center these two species are over-abundant relative to methanol, possibly an indication of formation of the species at low temperatures in CO-rich ices during the infall of the material toward the central protostar. Both 13 C and deuterated isotopologues of glycolaldehyde are detected, also for the first time ever in the ISM. For the deuterated species a D/H ratio of ≈5% is found with no differences between the deuteration in the different functional groups of glycolaldehyde, in contrast to previous estimates for methanol and recent suggestions of significant equilibration between water and -OH functional groups at high temperatures. Measurements of the 13 C-species lead to a 12 C: 13 C ratio of ≈30, lower than the typical ISM value. This low ratio may reflect an enhancement of 13 CO in the ice due to either ion-molecule reactions in the gas before freeze-out or differences in the temperatures where 12 CO and 13 CO ices sublimate. Conclusions. The results reinforce the importance of low temperature grain surfac...

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Section: Isotopologues Of Glycolaldehydementioning

confidence: 99%

The ALMA Protostellar Interferometric Line Survey (PILS)

Jørgensen

Wiel

Coutens

et al. 2016

A&A

380

582

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“…The millimeter-and submillimeter-wave spectra were recorded using the Lille spectrometer that is based on solid-state sources (Motiyenko et al 2010;Haykal et al 2013a …”

Section: Lille -Submillimeter Spectramentioning

confidence: 99%

THz spectroscopy and first ISM detection of excited torsional states of¹³C-methyl formate

Haykal¹,

Carvajal²,

Tercero³

et al. 2014

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Context. An astronomical survey of interstellar molecular clouds needs a previous analysis of the spectra in the microwave and sub-mm energy range of organic molecules to be able to identify them. We obtained very accurate spectroscopic constants in a comprehensive laboratory analysis of rotational spectra. These constants can be used to predict the transitions frequencies very precisely that were not measured in the laboratory. Aims. We present the experimental study and its theoretical analysis for two 13 C-methyl formate isotopologues to detect these two isotopologues for the first time in their excited torsional states, which lie at 130 cm −1 (200 K) in Orion-KL. Methods. New spectra of HCOO 13 CH 3 ( 13 C 2 ) methyl formate were recorded with the mm-and submm-wave spectrometer in Lille from 50 to 940 GHz. A global fit for v t = 0 and 1 was accomplished with the BELGI program to reproduce the experimental spectra with greater accuracy. Results. We analysed 5728 and 2881 new lines for v t = 0 and 1 for HCOO 13 CH 3 . These new lines were globally fitted with 846 previously published lines for v t = 0. In consequence, 52 parameters of the RAM Hamiltonian were accurately determined and the value of the barrier height (V 3 = 369.93168(395) cm −1 ) was improved. We report the detection of the first excited torsional states (v t = 1) in Orion-KL for the 13 C 2 and 13 C 1 methyl formate based on the present analysis and previously published data. We provide column densities, isotopic abundances, and vibrational temperatures for these species. Conclusions. Following this work, accurate prediction can be provided. This permits detecting 135 features of the first excited torsional states of 13 C-methyl formate isotopologues in Orion-KL in the 80−280 GHz frequency range, without missing lines.

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“…This paper is a continuation of a series of studies conducted in PhLAM Lille (France) that are devoted to the investigations of the spectra of different isotopic species of astrophysical molecules (Demyk et al 2007;Margulès et al 2009aMargulès et al ,b, 2010Carvajal et al 2009;Tercero et al 2012;Bouchez et al 2012;Coudert et al 2012Coudert et al , 2013Richard et al 2012Richard et al , 2013Haykal et al 2013;Kutsenko et al 2013;Nguyen et al 2013). In particular, these works led to the first interstellar detection of HCOOCH 2 D (Coudert et al 2013), HCOO 13 CH 3 (Carvajal et al 2009), HCO 18 OCH 3 , HC 18 OOCH 3 (Tercero et al 2012), and CH 2 DOCH 3 (Richard et al 2013).…”

Section: Introductionmentioning

confidence: 89%

Millimeter and submillimeter wave spectra of mono-¹³C-acetaldehydes

Margulès

Motiyenko

Ilyushin

et al. 2015

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Context. The acetaldehyde molecule is ubiquitous in the interstellar medium of our galaxy, and due to its dense and complex spectrum, large dipole moment, and several low-lying torsional states, acetaldehyde is considered to be a "weed" molecule for radio astronomy observations. Mono-13 C acetaldehydes 13 CH 3 CHO and CH 3 13 CHO are likely to be identified in astronomical surveys, such as those available with the very sensitive ALMA telescope. Laboratory measurements and analysis of the millimeter and submillimeter-wave spectra are the prerequisites for the successful radioastronomical search for the new interstellar molecular species, as well as for new isotopologs of already detected interstellar molecules. Aims. In this context, to provide reliable predictions of 13 CH 3 CHO and CH 3 13 CHO spectra in millimeter and submillimeter wave ranges, we study rotational spectra of these species in the frequency range from 50 to 945 GHz. Methods. The spectra of mono-13 C acetaldehydes were recorded using the spectrometer based on Schottky-diode frequencymultiplication chains in the Lille laboratory. The rotational spectra of 13 CH 3 CHO and CH 3 13 CHO molecules were analyzed using the Rho axis method. Results. In the recorded spectra we have assigned 6884 for the 13 CH 3 CHO species and 6458 for CH 3 13 CHO species new rotational transitions belonging to the ground, first, and second excited torsional states. These measurements were fitted together with previously published data to the Hamiltonian models that use 91 and 87 parameters to achieve overall weighted rms deviations 0.88 for the 13 CH 3 CHO species and 0.95 for CH 3 13 CHO. On the basis of the new spectroscopic results, predictions of transition frequencies in the frequency range up to 1 THz with J ≤ 60 and K a ≤ 20 are presented for both isotopologs.

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Millimeter and submillimeter wave spectra of¹³C-glycolaldehydes

Cited by 18 publications

References 15 publications

The ALMA Protostellar Interferometric Line Survey (PILS)

The ALMA Protostellar Interferometric Line Survey (PILS)

THz spectroscopy and first ISM detection of excited torsional states of¹³C-methyl formate

Millimeter and submillimeter wave spectra of mono-¹³C-acetaldehydes

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Millimeter and submillimeter wave spectra of13C-glycolaldehydes

Cited by 18 publications

References 15 publications

The ALMA Protostellar Interferometric Line Survey (PILS)

The ALMA Protostellar Interferometric Line Survey (PILS)

THz spectroscopy and first ISM detection of excited torsional states of13C-methyl formate

Millimeter and submillimeter wave spectra of mono-13C-acetaldehydes

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Millimeter and submillimeter wave spectra of¹³C-glycolaldehydes

THz spectroscopy and first ISM detection of excited torsional states of¹³C-methyl formate

Millimeter and submillimeter wave spectra of mono-¹³C-acetaldehydes