Rotational spectrum of deuterated and $\mathsf{^{15}}$N ethyl cyanides: CH3CHDCN and CH2DCH2CN and of CH3CH2C$\mathsf{^{15}}$N

Margulès, L.; Motiyenko, R. A.; Demyk, K.; Tercero, B.; Cernicharo, J.; Sheng, M.; Weidmann, M.; Gripp, J.; Mäder, H.; Demaison, J.

doi:10.1051/0004-6361:200810889

Cited by 36 publications

(31 citation statements)

References 17 publications

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“…In 2007 we began a close collaboration between astronomers and spectroscopists to reduce the uncertainty due to unidentified lines in spectral surveys. New isotopologues of ethyl cyanide and methyl formate (Demyk et al 2007;Margulès et al 2009Margulès et al , 2010Carvajal et al 2009;Coudert et al 2013) and new vibrationally excited states of formamide (Motiyenko et al 2012), ethyl cyanide , and vinyl cyanide (López et al 2014) have been studied in spectroscopy laboratories and detected in Orion KL for the first time space. Altogether, we reduced 3000 of unidentified lines through these studies.…”

Section: Resultsmentioning

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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Section: Resultsmentioning

confidence: 99%

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

Haykal¹,

Carvajal²,

Tercero³

et al. 2014

A&A

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“…The 13 C isotopomers of ethyl cyanide were detected first in Orion IRc2 (Demyk et al 2007) and soon thereafter in Sgr B2(N) (Müller et al 2008). Margulès et al (2009) reported the detection of C 2 H 5 C 15 N in Orion IRc2.…”

Section: Introductionmentioning

confidence: 91%

Spectroscopic study and astronomical detection of doubly¹³C-substituted ethyl cyanide

Margulès

Беллоче

Müller

et al. 2016

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Context. We have performed a spectral line survey called Exploring Molecular Complexity with ALMA (EMoCA) toward Sagittarius B2(N) between 84.1 and 114.4 GHz with the Atacama Large Millimeter/submillimeter Array (ALMA) in its Cycles 0 and 1. Line intensities of the main isotopic species of ethyl cyanide and its singly 13 C-substituted isotopomers observed toward the hot molecular core Sagittarius B2(N2) suggest that the doubly 13 C-substituted isotopomers should also be detectable. Aims. We want to determine the spectroscopic parameters of all three doubly 13 C-substituted isotopologues of ethyl cyanide to search for them in our ALMA data. Methods. We investigated the laboratory rotational spectra of the three species between 150 GHz and 990 GHz. We searched for emission lines produced by these species in the ALMA spectrum of Sagittarius B2(N2). We modeled their emission and the emission of the 12 C and singly 13 C-substituted isotopologues assuming local thermodynamic equilibrium. Results. We identified more than 5000 rotational transitions, pertaining to more than 3500 different transition frequencies, in the laboratory for each of the three doubly 13 C-substituted isotopomers. The quantum numbers reach J ≈ 115 and K a ≈ 35, resulting in accurate spectroscopic parameters and accurate rest frequency calculations beyond 1000 GHz for strong to moderately weak transitions of either isotopomer. All three species are unambiguously detected in our ALMA data. The 12 C/ 13 C column density ratio of the isotopomers with one 13 C atom to those with two 13 C atoms is about 25. Conclusions. Ethyl cyanide is the second molecule after methyl cyanide for which isotopologues containing two 13 C atoms have been securely detected in the interstellar medium. The model of our ethyl cyanide data suggests that we should be able to detect vibrational satellites of the main species up to at least 19 = 1 at ∼1130 K and up to 13 + 21 = 2 at ∼600 K for the isotopologues with one 13 C atom in our present ALMA data. Such satellites may be too weak to be identified unambiguously for isotopologues with two 13 C atoms.

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“…As an example of the scope of this line survey in the field of molecular spectroscopy, Demyk et al (2007), Margulès et al (2009), Carvajal et al (2009), and Margulès et al (2010 identified more than 600, 100, 600, and 100 lines from the 13 C and 15 N isotopologues of CH 3 CH 2 CN, the 13 C isotopologues of HCOOCH 3 , and CH 3 OCOD, respectively. Many of the remaining U-lines are certainly due to isotopologues of other abundant species.…”

Section: The Line Surveymentioning

confidence: 99%

A line confusion limited millimeter survey of Orion KL I. Sulfur carbon chains

Tercero

Cernicharo

Pardo

et al. 2010

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155

250

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We perform a sensitive (line confusion limited), single-side band spectral survey towards Orion KL with the IRAM 30 m telescope, covering the following frequency ranges: 80−115.5 GHz, 130−178 GHz, and 197−281 GHz. We detect more than 14 400 spectral features of which 10 040 have been identified up to date and attributed to 43 different molecules, including 148 isotopologues and lines from vibrationally excited states. In this paper, we focus on the study of OCS, HCS + , H 2 CS, CS, CCS, C 3 S, and their isotopologues. In addition, we map the OCS J = 18−17 line and complete complementary observations of several OCS lines at selected positions around Orion IRc2 (the position selected for the survey). We report the first detection of OCS ν 2 = 1 and ν 3 = 1 vibrationally excited states in space and the first detection of C 3 S in warm clouds. Most of CCS, and almost all C 3 S, line emission arises from the hot core indicating an enhancement of their abundances in warm and dense gas. Column densities and isotopic ratios have been calculated using a large velocity gradient (LVG) excitation and radiative transfer code (for the low density gas components) and a local thermal equilibrium (LTE) code (appropriate for the warm and dense hot core component), which takes into account the different cloud components known to exist towards Orion KL, the extended ridge, compact ridge, plateau, and hot core. The vibrational temperature derived from OCS ν 2 = 1 and ν 3 = 1 levels is 210 K, similar to the gas kinetic temperature in the hot core. These OCS high energy levels are probably pumped by absorption of IR dust photons. We derive an upper limit to the OC 3 S, H 2 CCS, HNCS, HOCS + , and NCS column densities. Finally, we discuss the D/H abundance ratio and infer the following isotopic abundances: 12 C/ 13 C = 45 ± 20, 32 S/ 34 S = 20 ± 6, 32 S/ 33 S = 75 ± 29, and 16 O/ 18 O = 250 ± 135.

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Rotational spectrum of deuterated and $\mathsf{^{15}}$N ethyl cyanides: CH₃CHDCN and CH₂DCH₂CN and of CH₃CH₂C$\mathsf{^{15}}$N

Cited by 36 publications

References 17 publications

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

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

Spectroscopic study and astronomical detection of doubly¹³C-substituted ethyl cyanide

A line confusion limited millimeter survey of Orion KL I. Sulfur carbon chains

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Rotational spectrum of deuterated and $\mathsf{^{15}}$N ethyl cyanides: CH3CHDCN and CH2DCH2CN and of CH3CH2C$\mathsf{^{15}}$N

Cited by 36 publications

References 17 publications

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

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

Spectroscopic study and astronomical detection of doubly13C-substituted ethyl cyanide

A line confusion limited millimeter survey of Orion KL I. Sulfur carbon chains

Contact Info

Product

Resources

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Rotational spectrum of deuterated and $\mathsf{^{15}}$N ethyl cyanides: CH₃CHDCN and CH₂DCH₂CN and of CH₃CH₂C$\mathsf{^{15}}$N

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

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

Spectroscopic study and astronomical detection of doubly¹³C-substituted ethyl cyanide