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Cernicharo J, Cabezas C, Endo Y, Agúndez M, Tercero B, Pardo JR, Marcelino N, de Vicente P. The sulphur saga in TMC-1: Discovery of HCSCN and HCSCCH. Astron Astrophys 2021; 650:L14. [PMID: 34334797 PMCID: PMC7611419 DOI: 10.1051/0004-6361/202141297] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We report the detection, for the first time in space, of cyano thioformaldehyde (HCSCN) and propynethial (HCSCCH) towards the starless core TMC-1. Cyano thioformaldehyde presents a series of prominent a- and b-type lines, which are the strongest previously unassigned features in our Q-band line survey of TMC-1. Remarkably, HCSCN is four times more abundant than cyano formaldehyde (HCOCN). On the other hand, HCSCCH is five times less abundant than propynal (HCOCCH). Surprisingly, we find an abundance ratio HCSCCH/HCSCN of ∼ 0.25, in contrast with most other ethynyl-cyanide pairs of molecules for which the CCH-bearing species is more abundant than the CN-bearing one. We discuss the formation of these molecules in terms of neutral-neutral reactions of S atoms with CH2CCH and CH2CN radicals as well as of CCH and CN radicals with H2CS. The calculated abundances for the sulphur-bearing species are, however, significantly below the observed values, which points to an underestimation of the abundance of atomic sulphur in the model or to missing formation reactions, such as ion-neutral reactions.
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Affiliation(s)
- J Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C / Serrano 121, 28006 Madrid, Spain
| | - C Cabezas
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C / Serrano 121, 28006 Madrid, Spain
| | - Y Endo
- Department of Applied Chemistry, Science Building II, National Yang Ming Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan
| | - M Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C / Serrano 121, 28006 Madrid, Spain
| | - B Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (IGN), C/Alfonso XII, 3, 28014, Madrid, Spain
| | - J R Pardo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C / Serrano 121, 28006 Madrid, Spain
| | - N Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C / Serrano 121, 28006 Madrid, Spain
| | - P de Vicente
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
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Cabezas C, Roueff E, Tercero B, Agúndez M, Marcelino N, de Vicente P, Cernicharo J. Detection of deuterated methylcyanoacetylene, CH 2DC 3N, in TMC-1. Astron Astrophys 2021; 650:L15. [PMID: 34321677 PMCID: PMC7611387 DOI: 10.1051/0004-6361/202141371] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We report the first detection in space of the single deuterated isotopologue of methylcyanoacetylene, CH2DC3N. A total of fifteen rotational transitions, with J = 8-12 and Ka = 0 and 1, were identified for this species in TMC-1 in the 31.0-50.4 GHz range using the Yebes 40m radio telescope. The observed frequencies were used to derive for the first time the spectroscopic parameters of this deuterated isotopologue. We derive a column density of (8.0 ± 0.4) × 1010 cm-2. The abundance ratio between CH3C3N and CH2DC3N is ∼22. We also theoretically computed the principal spectroscopic constants of 13C isotopologues of CH3C3N and CH3C4H and those of the deuterated isotopologues of CH3C4H for which we could expect a similar degree of deuteration enhancement. However, we have not detected either CH2DC4H nor CH3C4D nor any 13C isotopologue. The different observed deuterium ratios in TMC-1 are reasonably accounted for by a gas phase chemical model where the low temperature conditions favor deuteron transfer through reactions with H2D+.
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Affiliation(s)
- C Cabezas
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - E Roueff
- LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, 92190 Meudon, France
| | - B Tercero
- Observatorio Astronómico Nacional (IGN), C/ Alfonso XII, 3, 28014, Madrid, Spain
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - M Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - N Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - P de Vicente
- Observatorio Astronómico Nacional (IGN), C/ Alfonso XII, 3, 28014, Madrid, Spain
| | - J Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
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Cabezas C, Tercero B, Agúndez M, Marcelino N, Pardo JR, de Vicente P, Cernicharo J. Cumulene carbenes in TMC-1: Astronomical discovery of l-H 2C 5 ★. Astron Astrophys 2021; 650:L9. [PMID: 34334798 PMCID: PMC7611420 DOI: 10.1051/0004-6361/202141274] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We report the first detection in space of the cumulene carbon chain l-H2C5. A total of eleven rotational transitions, with Jup = 7-10 and Ka = 0 and 1, were detected in TMC-1 in the 31.0-50.4 GHz range using the Yebes 40m radio telescope. We derive a column density of (1.8±0.5)×1010 cm-2. In addition, we report observations of other cumulene carbenes detected previously in TMC-1, to compare their abundances with the newly detected cumulene carbene chain. We find that l-H2C5 is ~4.0 times less abundant than the larger cumulene carbene l-H2C6, while it is ~300 and ~500 times less abundant than the shorter chains l-H2C3 and l-H2C4. We discuss the most likely gas-phase chemical routes to these cumulenes in TMC-1 and stress that chemical kinetics studies able to distinguish between different isomers are needed to shed light on the chemistry of C n H2 isomers with n > 3.
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Affiliation(s)
- C. Cabezas
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - B. Tercero
- Observatorio Astronómico Nacional (IGN), C/ Alfonso XII, 3, 28014, Madrid, Spain
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - M. Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - N. Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - J. R. Pardo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - P. de Vicente
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J. Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
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Cernicharo J, Agúndez M, Cabezas C, Tercero B, Marcelino N, Pardo JR, de Vicente P. Pure hydrocarbon cycles in TMC-1: Discovery of ethynyl cyclopropenylidene, cyclopentadiene and indene. Astron Astrophys 2021; 649:L15. [PMID: 34257463 PMCID: PMC7611194 DOI: 10.1051/0004-6361/202141156] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report the detection for the first time in space of three new pure hydrocarbon cycles in TMC-1: c-C3HCCH (ethynyl cyclopropenylidene), c-C5H6 (cyclopentadiene) and c-C9H8 (indene). We derive a column density of 3.1 × 1011 cm-2 for the former cycle and similar values, in the range (1-2) × 1013 cm-2, for the two latter molecules. This means that cyclopentadiene and indene, in spite of their large size, are exceptionally abundant, only a factor of five less abundant than the ubiquitous cyclic hydrocarbon c-C3H2. The high abundance found for these two hydrocarbon cycles, together with the high abundance previously found for the propargyl radical (CH2CCH) and other hydrocarbons like vinyl and allenyl acetylene (Agúndez et al. 2021; Cernicharo et al. 2021a,b), start to allow us to quantify the abundant content of hydrocarbon rings in cold dark clouds and to identify the intermediate species that are probably behind the in situ bottom-up synthesis of aromatic cycles in these environments. While c-C3HCCH is most likely formed through the reaction between the radical CCH and c-C3H2, the high observed abundances of cyclopentadiene and indene are difficult to explain through currently proposed chemical mechanisms. Further studies are needed to identify how are five- and six-membered rings formed under the cold conditions of clouds like TMC-1.
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Affiliation(s)
- J. Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - M. Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - C. Cabezas
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - B. Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (OAN, IGN), Madrid, Spain
| | - N. Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - J. R. Pardo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - P. de Vicente
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
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Agúndez M, Marcelino N, Tercero B, Cabezas C, de Vicente P, Cernicharo J. O-bearing complex organic molecules at the cyanopolyyne peak of TMC-1: detection of C 2H 3CHO, C 2H 3OH, HCOOCH 3, and CH 3OCH 3. Astron Astrophys 2021; 649:L4. [PMID: 34334796 PMCID: PMC7611417 DOI: 10.1051/0004-6361/202140978] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We report the detection of the oxygen-bearing complex organic molecules propenal (C2H3CHO), vinyl alcohol (C2H3OH), methyl formate (HCOOCH3), and dimethyl ether (CH3OCH3) toward the cyanopolyyne peak of the starless core TMC-1. These molecules are detected through several emission lines in a deep Q-band line survey of TMC-1 carried out with the Yebes 40m telescope. These observations reveal that the cyanopolyyne peak of TMC-1, which is the prototype of cold dark cloud rich in carbon chains, contains also O-bearing complex organic molecules like HCOOCH3 and CH3OCH3, which have been previously seen in a handful of cold interstellar clouds. In addition, this is the first secure detection of C2H3OH in space and the first time that C2H3CHO and C2H3OH are detected in a cold environment, adding new pieces in the puzzle of complex organic molecules in cold sources. We derive column densities of (2.2 ± 0.3) × 1011 cm™2, (2.5 ± 0.5) × 1012 cm-2, (1.1 ± 0.2) × 1012 cm-2, and (2.5 ± 0.7) × 1012 cm-2 for C2H3CHO, C2H3OH, HCOOCH3, and CH3OCH3, respectively. Interestingly, C2H3OH has an abundance similar to that of its well known isomer acetaldehyde (CH3CHO), with C2H3OH/CH3CHO ~ 1 at the cyanopolyyne peak. We discuss potential formation routes to these molecules and recognize that further experimental, theoretical, and astronomical studies are needed to elucidate the true mechanism of formation of these O-bearing complex organic molecules in cold interstellar sources.
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Affiliation(s)
- M. Agúndez
- Instituto de Física Fundamental, CSIC, Calle Serrano 123, E-28006 Madrid, Spain
| | - N. Marcelino
- Instituto de Física Fundamental, CSIC, Calle Serrano 123, E-28006 Madrid, Spain
| | - B. Tercero
- Observatorio Astronómico Nacional, IGN, Calle Alfonso XII 3, E-28014 Madrid, Spain
- Observatorio de Yebes, IGN, Cerro de la Palera s/n, E-19141 Yebes, Guadalajara, Spain
| | - C. Cabezas
- Instituto de Física Fundamental, CSIC, Calle Serrano 123, E-28006 Madrid, Spain
| | - P. de Vicente
- Observatorio de Yebes, IGN, Cerro de la Palera s/n, E-19141 Yebes, Guadalajara, Spain
| | - J. Cernicharo
- Instituto de Física Fundamental, CSIC, Calle Serrano 123, E-28006 Madrid, Spain
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Cernicharo J, Cabezas C, Agúndez M, Tercero B, Pardo JR, Marcelino N, Gallego J, Tercero F, López-Pérez J, de Vicente P. TMC-1, the starless core sulfur factory: Discovery of NCS, HCCS, H 2CCS, H 2CCCS, and C 4S and detection of C 5S. Astron Astrophys 2021; 648:L3. [PMID: 33850333 PMCID: PMC7610586 DOI: 10.1051/0004-6361/202140642] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We report the detection of the sulfur-bearing species NCS, HCCS, H2CCS, H2CCCS, and C4S for the first time in space. These molecules were found towards TMC-1 through the observation of several lines for each species. We also report the detection of C5S for the first time in a cold cloud through the observation of five lines in the 31-50 GHz range. The derived column densities are N(NCS) = (7.8±0.6)×1011 cm-2, N(HCCS) = (6.8±0.6)×1011 cm-2, N(H2CCS) = (7.8±0.8)×1011 cm-2, N(H2CCCS) = (3.7±0.4)×1011 cm-2, N(C4S) = (3.8±0.4)×1010 cm-2, and N(C5S) = (5.0±1.0)×1010 cm-2. The observed abundance ratio between C3S and C4S is 340, that is to say a factor of approximately one hundred larger than the corresponding value for CCS and C3S. The observational results are compared with a state-of-the-art chemical model, which is only partially successful in reproducing the observed abundances. These detections underline the need to improve chemical networks dealing with S-bearing species.
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Affiliation(s)
- J. Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - C. Cabezas
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - M. Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - B. Tercero
- Observatorio Astronómico Nacional (IGN), C/ Alfonso XII, 3, 28014, Madrid, Spain
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J. R. Pardo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - N. Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - J.D. Gallego
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - F. Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J.A. López-Pérez
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - P. de Vicente
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
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Cernicharo J, Agúndez M, Cabezas C, Marcelino N, Tercero B, Pardo JR, Gallego JD, Tercero F, López-Pérez JA, de Vicente P. Discovery of CH 2CHCCH and detection of HCCN, HC 4N, CH 3CH 2CN, and, tentatively, CH 3CH 2CCH in TMC-1. Astron Astrophys 2021; 647:L2. [PMID: 33833468 PMCID: PMC7610549 DOI: 10.1051/0004-6361/202140434] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present the discovery in TMC-1 of vinyl acetylene, CH2CHCCH, and the detection, for the first time in a cold dark cloud, of HCCN, HC4N, and CH3CH2CN. A tentative detection of CH3CH2CCH is also reported. The column density of vinyl acetylene is (1.2±0.2)×1013 cm-2, which makes it one of the most abundant closed-shell hydrocarbons detected in TMC-1. Its abundance is only three times lower than that of propylene, CH3CHCH2. The column densities derived for HCCN and HC4N are (4.4±0.4)×1011 cm-2 and (3.7±0.4)×1011 cm-2, respectively. Hence, the HCCN/HC4N abundance ratio is 1.2±0.3. For ethyl cyanide we derive a column density of (1.1 ±0.3)×1011 cm-2. These results are compared with a state-of-the-art chemical model of TMC-1, which is able to account for the observed abundances of these molecules through gas-phase chemical routes.
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Affiliation(s)
- J Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - M Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - C Cabezas
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - N Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - B Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (IGN), C/ Alfonso XII, 3, 28014, Madrid, Spain
| | - J R Pardo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - J D Gallego
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - F Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J A López-Pérez
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - P de Vicente
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
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Cernicharo J, Cabezas C, Agúndez M, Tercero B, Marcelino N, Pardo JR, Tercero F, Gallego J, López-Pérez J, deVicente P. Discovery of allenyl acetylene, H 2CCCHCCH, in TMC-1. A study of the isomers of C 5H 4. Astron Astrophys 2021; 647:L3. [PMID: 33850332 PMCID: PMC7610584 DOI: 10.1051/0004-6361/202140482] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We present the discovery in TMC-1 of allenyl acetylene, H2CCCHCCH, through the observation of nineteen lines with a signal-to-noise ratio ~4-15. For this species, we derived a rotational temperature of 7±1K and a column density of 1.2±0.2×1013 cm-2. The other well known isomer of this molecule, methyl diacetylene (CH3C4H), has also been observed and we derived a similar rotational temperature, Tr=7.0±0.3 K, and a column density for its two states (A and E) of 6.5±0.3×1012 cm-2. Hence, allenyl acetylene and methyl diacetylene have a similar abundance. Remarkably, their abundances are close to that of vinyl acetylene (CH2CHCCH). We also searched for the other isomer of C5H4, HCCCH2CCH (1.4-Pentadiyne), but only a3σ upper limit of 2.5×1012 cm-2 to the column density can be established. These results have been compared to state-of-the-art chemical models for TMC-1, indicating the important role of these hydrocarbons in its chemistry. The rotational parameters of allenyl acetylene have been improved by fitting the existing laboratory data together with the frequencies of the transitions observed in TMC-1.
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Affiliation(s)
- J. Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - C. Cabezas
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - M. Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - B. Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (OAN, IGN), Madrid, Spain
| | - N. Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - J. R. Pardo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - F. Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J.D. Gallego
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J.A. López-Pérez
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - P. deVicente
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
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Agúndez M, Cabezas C, Tercero B, Marcelino N, Gallego JD, de Vicente P, Cernicharo J. Discovery of the propargyl radical (CH 2CCH) in TMC-1: one of the most abundant radicals ever found and a key species for cyclization to benzene in cold dark clouds. Astron Astrophys 2021; 647:L10. [PMID: 33850331 PMCID: PMC7610583 DOI: 10.1051/0004-6361/202140553] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We present the first identification in interstellar space of the propargyl radical (CH2CCH). This species was observed in the cold dark cloud TMC-1 using the Yebes 40m telescope. The six strongest hyperfine components of the 20,2-10,1 rotational transition, lying at 37.46 GHz, were detected with signal-to-noise ratios in the range 4.6-12.3 σ. We derive a column density of 8.7 × 1013 cm-2 for CH2CCH, which translates to a fractional abundance relative to H2 of 8.7 × 10-9. This radical has a similar abundance to methyl acetylene, with an abundance ratio CH2CCH/CH3CCH close to one. The propargyl radical is thus one of the most abundant radicals detected in TMC-1, and it is probably the most abundant organic radical with a certain chemical complexity ever found in a cold dark cloud. We constructed a gas-phase chemical model and find calculated abundances that agree with, or fall two orders of magnitude below, the observed value depending on the poorly constrained low-temperature reactivity of CH2CCH with neutral atoms. According to the chemical model, the propargyl radical is essentially formed by the C + C2H4 reaction and by the dissociative recombination of C3Hn + ions with n = 4-6. The propargyl radical is believed to control the synthesis of the first aromatic ring in combustion processes, and it probably plays a key role in the synthesis of large organic molecules and cyclization processes to benzene in cold dark clouds.
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Affiliation(s)
- M. Agúndez
- Instituto de Física Fundamental, CSIC, Calle Serrano 123, E-28006 Madrid, Spain
| | - C. Cabezas
- Instituto de Física Fundamental, CSIC, Calle Serrano 123, E-28006 Madrid, Spain
| | - B. Tercero
- Observatorio Astronómico Nacional, IGN, Calle Alfonso XII 3, E-28014 Madrid, Spain
- Observatorio de Yebes, IGN, Cerro de la Palera s/n, E-19141 Yebes, Guadalajara, Spain
| | - N. Marcelino
- Instituto de Física Fundamental, CSIC, Calle Serrano 123, E-28006 Madrid, Spain
| | - J. D. Gallego
- Observatorio de Yebes, IGN, Cerro de la Palera s/n, E-19141 Yebes, Guadalajara, Spain
| | - P. de Vicente
- Observatorio de Yebes, IGN, Cerro de la Palera s/n, E-19141 Yebes, Guadalajara, Spain
| | - J. Cernicharo
- Instituto de Física Fundamental, CSIC, Calle Serrano 123, E-28006 Madrid, Spain
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10
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Abstract
We present Yebes 40m telescope observations of the three most stable C4H3N isomers towards the cyanopolyyne peak of TMC-1. We have detected 13 transitions from CH3C3N (A and E species), 16 lines from CH2CCHCN, and 27 lines (a-type and b-type) from HCCCH2CN. We thus provide a robust confirmation of the detection of HCCCH2CN and CH2CCHCN in space. We have constructed rotational diagrams for the three species, and obtained rotational temperatures between 4-8 K and similar column densities for the three isomers, in the range (1.5-3)×1012 cm-2. Our chemical model provides abundances of the order of the observed ones, although it overestimates the abundance of CH3CCCN and underestimates that of HCCCH2CN. The similarity of the observed abundances of the three isomers suggests a common origin, most probably involving reactions of the radical CN with the unsaturated hydrocarbons methyl acetylene and allene. Studies of reaction kinetics at low temperature and further observations of these molecules in different astronomical sources are needed to draw a clear picture of the chemistry of C4H3N isomers in space.
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Affiliation(s)
- N. Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental, CSIC, C/ Serrano 123, 28006 Madrid, Spain
| | - B. Tercero
- Observatorio Astronómico Nacional (IGN), C/ Alfonso XII 3, 28014 Madrid, Spain
- Observatorio de Yebes (IGN). Cerro de la Palera s/n, 19141 Yebes, Guadalajara, Spain
| | - M. Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental, CSIC, C/ Serrano 123, 28006 Madrid, Spain
| | - J. Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental, CSIC, C/ Serrano 123, 28006 Madrid, Spain
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Cernicharo J, Cabezas C, Endo Y, Marcelino N, Agúndez M, Tercero B, Gallego JD, de Vicente P. Space and laboratory discovery of HC 3 S. Astron Astrophys 2021; 646:L3. [PMID: 33824540 PMCID: PMC7610522 DOI: 10.1051/0004-6361/202040013] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We report the detection in TMC-1 of the protonated form of C3S. The discovery of the cation HC3S+ was carried through the observation of four harmonically related lines in the Q band using the Yebes 40m radiotelescope, and is supported by accurate ab initio calculations and laboratory measurements of its rotational spectrum. We derive a column density N(HC3S+) = (2.0 ± 0.5) × 1011 cm-2, which translates to an abundance ratio C3S/HC3S+ of 65 ± 20. This ratio is comparable to the CS/HCS+ ratio (35 ± 8) and is a factor of about ten larger than the C3O/HC3O+ ratio previously found in the same source. However, the abundance ratio HC3O+/HC3S+ is 1.0 ± 0.5, while C3O/C3S is just ~ 0.11. We also searched for protonated C2S in TMC-1, based on ab initio calculations of its spectroscopic parameters, and derive a 3σ upper limit of N(HC2S+)≤ 9×1011 cm-2 and a C2S/HC2S+ ≥ 60. The observational results are compared with a state-of-the-art gas-phase chemical model and conclude that HC3S+ is mostly formed through several pathways: proton transfer to C3S, reaction of S+ with c-C3H2, and reaction between neutral atomic sulfur and the ion C3H+ 3.
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Affiliation(s)
- J Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - C Cabezas
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - Y Endo
- Department of Applied Chemistry, Science Building II, National Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan
| | - N Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - M Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - B Tercero
- Observatorio Astronómico Nacional (IGN), C/ Alfonso XII, 3, 28014, Madrid, Spain
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J D Gallego
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - P de Vicente
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
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12
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Cernicharo J, Cabezas C, Bailleux S, Margulès L, Motiyenko R, Zou L, Endo Y, Bermúdez C, Agúndez M, Marcelino N, Lefloch B, Tercero B, de Vicente P. Discovery of the acetyl cation, CH 3CO +, in space and in the laboratory. Astron Astrophys 2021; 646:L7. [PMID: 33828331 PMCID: PMC7610537 DOI: 10.1051/0004-6361/202040076] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Using the Yebes 40m and IRAM 30m radiotelescopes, we detected two series of harmonically related lines in space that can be fitted to a symmetric rotor. The lines have been seen towards the cold dense cores TMC-1, L483, L1527, and L1544. High level of theory ab initio calculations indicate that the best possible candidate is the acetyl cation, CH3CO+, which is the most stable product resulting from the protonation of ketene. We have produced this species in the laboratory and observed its rotational transitions Ju = 10 up to Ju = 27. Hence, we report the discovery of CH3CO+ in space based on our observations, theoretical calculations, and laboratory experiments. The derived rotational and distortion constants allow us to predict the spectrum of CH3CO+ with high accuracy up to 500 GHz. We derive an abundance ratio N(H2CCO)/N(CH3CO+)~44. The high abundance of the protonated form of H2CCO is due to the high proton affinity of the neutral species. The other isomer, H2CCOH+, is found to be 178.9 kJ mol-1 above CH3CO+. The observed intensity ratio between the K=0 and K=1 lines, ~2.2, strongly suggests that the A and E symmetry states have suffered interconversion processes due to collisions with H and/or H2, or during their formation through the reaction of H 3 + with H2CCO.
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Affiliation(s)
- J Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - C Cabezas
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - S Bailleux
- Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, 59000 Lille, France
| | - L Margulès
- Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, 59000 Lille, France
| | - R Motiyenko
- Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, 59000 Lille, France
| | - L Zou
- Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, 59000 Lille, France
| | - Y Endo
- Department of Applied Chemistry, Science Building II, National Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan
| | - C Bermúdez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - M Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - N Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - B Lefloch
- CNRS, IPAG, Univ. Grenoble Alpes, F-38000 Grenoble, France
| | - B Tercero
- Observatorio Astronómico Nacional (IGN), C/ Alfonso XII, 3, 28014, Madrid, Spain
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - P de Vicente
- Observatorio Astronómico Nacional (IGN), C/ Alfonso XII, 3, 28014, Madrid, Spain
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13
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Tercero F, López-Pérez JA, Gallego JD, Beltrán F, García O, Patino-Esteban M, López-Fernández I, Gómez-Molina G, Diez M, García-Carreño P, Malo I, Amils R, Serna JM, Albo C, Hernández JM, Vaquero B, González-García J, Barbas L, López-Fernández JA, Bujarrabal V, Gómez-Garrido M, Pardo JR, Santander-García M, Tercero B, Cernicharo J, de Vicente P. Yebes 40 m radio telescope and the broad band NANOCOSMOS receivers at 7 mm and 3 mm for line surveys. Astron Astrophys 2021; 645:A37. [PMID: 33408420 PMCID: PMC7116543 DOI: 10.1051/0004-6361/202038701] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
CONTEXT Yebes 40m radio telescope is the main and largest observing instrument at Yebes Observatory and it is devoted to Very Long Baseline Interferometry (VLBI) and single dish observations since 2010. It has been covering frequency bands between 2 GHz and 90 GHz in discontinuous and narrow windows in most of the cases, to match the current needs of the European VLBI Network (EVN) and the Global Millimeter VLBI Array (GMVA). AIMS Nanocosmos project, a European Union funded synergy grant, opened the possibility to increase the instantaneous frequency coverage to observe many molecular transitions with single tunnings in single dish mode. This reduces the observing time and maximises the output from the telescope. METHODS We present the technical specifications of the recently installed 31.5 - 50GHz (Q band) and 72 - 90.5 GHz (W band) receivers along with the main characteristics of the telescope at these frequency ranges. We have observed IRC+10216, CRL 2688 and CRL 618, which harbour a rich molecular chemistry, to demonstrate the capabilities of the new instrumentation for spectral observations in single dish mode. RESULTS The results show the high sensitivity of the telescope in the Q band. The spectrum of IRC+10126 offers a signal to noise ratio never seen before for this source in this band. On the other hand, the spectrum normalised by the continuum flux towards CRL 618 in the W band demonstrates that the 40 m radio telescope produces comparable results to those from the IRAM 30 m radio telescope, although with a smaller sensitivity. The new receivers fulfil one of the main goals of Nanocosmos and open the possibility to study the spectrum of different astrophysical media with unprecedented sensitivity.
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Affiliation(s)
- F. Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J. A. López-Pérez
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J. D. Gallego
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - F. Beltrán
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - O. García
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - M. Patino-Esteban
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - I. López-Fernández
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - G. Gómez-Molina
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - M. Diez
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - P. García-Carreño
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - I. Malo
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - R. Amils
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J. M. Serna
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - C. Albo
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J. M. Hernández
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - B. Vaquero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J. González-García
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - L. Barbas
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | | | - V. Bujarrabal
- Observatorio Astronómico Nacional (IGN), C/ Alfonso XII, 3, 28014, Madrid, Spain
| | - M. Gómez-Garrido
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (IGN), C/ Alfonso XII, 3, 28014, Madrid, Spain
| | - J. R. Pardo
- Instituto de Física Fundamental (IFF-CSIC). Group of Molecular Astrophysics, C/ Serrano 123, 28006 Madrid, Spain
| | - M. Santander-García
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (IGN), C/ Alfonso XII, 3, 28014, Madrid, Spain
| | - B. Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (IGN), C/ Alfonso XII, 3, 28014, Madrid, Spain
| | - J. Cernicharo
- Instituto de Física Fundamental (IFF-CSIC). Group of Molecular Astrophysics, C/ Serrano 123, 28006 Madrid, Spain
| | - P. de Vicente
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
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Cabezas C, Neeman EM, Tercero B, Bermúdez C, Cernicharo J. Comprehensive rotational study and astronomical search for cyclopropanecarboxaldehyde. Astron Astrophys 2021; 645:A75. [PMID: 33833467 PMCID: PMC7610548 DOI: 10.1051/0004-6361/202039924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
CONTEXT At least a dozen molecules with a formyl group (HCO) have been observed to date in the interstellar medium (ISM), suggesting that other such species exist and remain to be discovered. However, there is still a lack of high-resolution spectroscopic data for simple molecular species of this type that could provide a basis for their detection. AIMS Cyclopropanecarboxaldehyde, c-C3H5CHO, is a small molecule containing a formyl group and is therefore an interesting candidate for astrophysical detection. The rotational spectrum of cyclopropanecarboxaldehyde has been observed before, but its experimental rotational parameters are not precise enough to allow its detection in the millimetre-wave domain. METHODS We measured the rotational spectrum of cyclopropanecarboxaldehyde in the frequency ranges 31.5-50 GHz and 72-116.5 GHz using the GACELA (GAS CEll for Laboratory Astrophysics) broadband high-resolution rotational spectrometer constructed at the Yebes Observatory. The spectroscopic study was supported by high-level theoretical calculations which were used in the identification of the vibrational excited states of cyclopropanecarboxaldehyde. RESULTS Our analysis of the rotational spectrum of cyclopropanecarboxaldehyde allowed us to obtain accurate rotational parameters for the ground state of both cis and trans isomers, which were used to derive sufficiently reliable predictions up to 300 GHz. In addition to the ground states, we identified 12 and 6 vibrationally excited states for the trans and cis isomers, respectively, including fundamental modes, multiple excitation quanta, and combination states. We find that the gas phase concentration of the trans isomer is almost 1.2 times larger than that of the cis one. These new experimental rotational parameters were employed to search for cyclopropanecarboxaldehyde in the warm molecular clouds Orion KL and Sgr B2(N) using the spectral surveys captured by ALMA (Orion) and IRAM 30 m (Sgr) at 1 mm and 3 mm, respectively.
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Affiliation(s)
- C. Cabezas
- Instituto de Física Fundamental (IFF-CSIC). Group of Molecular Astrophysics, C/Serrano 123, 28006 Madrid, Spain
| | - E. M. Neeman
- Departamento de Química Física. Facultad de Ciencias y Tecnologías Químicas. Universidad de Castilla-La Mancha. Avda. Camilo José Cela 1B. 13071, Ciudad Real, Spain
| | - B. Tercero
- Observatorio de Yebes (IGN), Cerro de la Palera s/n, 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (OAN-IGN), C/Alfonso XII 3, 28014 Madrid, Spain
| | - C. Bermúdez
- Instituto de Física Fundamental (IFF-CSIC). Group of Molecular Astrophysics, C/Serrano 123, 28006 Madrid, Spain
| | - J. Cernicharo
- Instituto de Física Fundamental (IFF-CSIC). Group of Molecular Astrophysics, C/Serrano 123, 28006 Madrid, Spain
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Jabri A, Tercero B, Margulès L, Motiyenko RA, Alekseev EA, Kleiner I, Cernicharo J, Guillemin JC. Rotational spectroscopic study of S-methyl thioformate: A global laboratory analysis of ground and excited torsional states up to 660 GHz. Astron Astrophys 2020; 644:A102. [PMID: 33594292 PMCID: PMC7116753 DOI: 10.1051/0004-6361/202038200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
CONTEXT S-methyl thioformate CH3SC(O)H is a monosulfur derivative of methyl formate, a relatively abundant component of the interstellar medium (ISM). S-methyl thioformate being, thermodynamically, the most stable isomer, it can be reasonably proposed for detection in the ISM. AIMS This work aims to experimentally study and theoretically analyze the ground and first torsional excited states for CH3SC(O)H in a large spectral range for astrophysical use. METHODS S-methyl thioformate was synthesized as a result of a reaction of methyl mercaptan with acetic-formic anhydride. The millimeter-wave spectrum was then recorded for the first time from 150 to 660 GHz with the solid-state spectrometer located at Lille. RESULTS A set of 3545 lines is determined and combined with 54 previously measured lines in the microwave region, belonging to ground state ν t = 0 as well as 1391 transitions in the first excited state of torsion ν 18 = 1. Some 164 lines were also assigned to ν 18 = 2 for the A-species. A global fit was performed using the BELGI-Cs code taking into account the large splitting of A and E lines due to methyl internal rotation motion with a relatively low barrier, V3 = 127.4846(15) cm-1. CONCLUSIONS Using our spectroscopy work, a deep search of S-methyl thioformate was carried out in the IRAM 30m and ALMA data of different high-mass star-forming regions (Orion KL and Sgr B2). We derived an upper limit to the CH3SC(O)H column density in these regions.
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Affiliation(s)
- A Jabri
- Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), UMR CNRS 7583, Université Paris-Est-Créteil, Université de Paris, Institut Pierre Simon Laplace (IPSL), 61 av. du Général de Gaulle, 94010 Créteil, France
| | - B Tercero
- Observatorio Astronómico Nacional (OAN-IGN). Calle Alfonso XII, 3, 28014 Madrid, Spain
- Observatorio de Yebes (IGN). Cerro de la Palera s/n, 19141 Yebes, Guadalajara, Spain
| | - L Margulès
- Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, 59000 Lille, France
| | - R A Motiyenko
- Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, 59000 Lille, France
| | - E A Alekseev
- Radiospectrometry Department, Institute of Radio Astronomy of NASU, Kharkov, Ukraine
| | - I Kleiner
- Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), UMR CNRS 7583, Université Paris-Est-Créteil, Université de Paris, Institut Pierre Simon Laplace (IPSL), 61 av. du Général de Gaulle, 94010 Créteil, France
| | - J Cernicharo
- Instituto de Física Fundamental (IFF-CSIC). Calle Serrano 123, 28006 Madrid, Spain
| | - J-C Guillemin
- Univ. Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR-UMR 6226, 35000 Rennes, France
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16
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Marcelino N, Agúndez M, Tercero B, Cabezas C, Bermúdez C, Gallego JD, de Vicente P, Cernicharo J. Tentative detection of HC 5NH + in TMC-1. Astron Astrophys 2020; 643:L6. [PMID: 33239826 PMCID: PMC7116411 DOI: 10.1051/0004-6361/202039251] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Using the Yebes 40m radio telescope, we report the detection of a series of seven lines harmonically related with a rotational constant B 0=1295.81581 ± 0.00026 MHz and a distortion constant D 0 = 27.3 ± 0.5 Hz towards the cold dense cloud TMC-1. Ab initio calculations indicate that the best possible candidates are the cations HC5NH+ and NC4NH+. From a comparison between calculated and observed rotational constants and other arguments based on proton affinities and dipole moments, we conclude that the best candidate for a carrier of the observed lines is the protonated cyanodiacetylene cation, HC5NH+. The HC5N/HC5NH+ ratio derived in TMC-1 is 240, which is very similar to the HC3N/HC3NH+ ratio. Results are discussed in the framework of a chemical model for protonated molecules in cold dense clouds.
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Affiliation(s)
- N Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - M Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - B Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (IGN), C/Alfonso XII, 3, 28014, Madrid, Spain
| | - C Cabezas
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - C Bermúdez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - J D Gallego
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - P de Vicente
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
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17
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Zeng S, Zhang Q, Jiménez-Serra I, Tercero B, Lu X, Martín-Pintado J, de Vicente P, Rivilla VM, Li S. Cloud-cloud collision as drivers of the chemical complexity in Galactic Centre molecular clouds. Mon Not R Astron Soc 2020; 497:4896-4909. [PMID: 33594294 PMCID: PMC7116751 DOI: 10.1093/mnras/staa2187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
G+0.693-0.03 is a quiescent molecular cloud located within the Sagittarius B2 (Sgr B2) star-forming complex. Recent spectral surveys have shown that it represents one of the most prolific repositories of complex organic species in the Galaxy. The origin of such chemical complexity, along with the small-scale physical structure and properties of G+0.693-0.03, remains a mystery. In this paper, we report the study of multiple molecules with interferometric observations in combination with single-dish data in G+0.693-0.03. Despite the lack of detection of continuum source, we find small-scale (0.2 pc) structures within this cloud. The analysis of the molecular emission of typical shock tracers such as SiO, HNCO, and CH3OH unveiled two molecular components, peaking at velocities of 57 and 75 km s-1. They are found to be interconnected in both space and velocity. The position-velocity diagrams show features that match with the observational signatures of a cloud-cloud collision. Additionally, we detect three series of class I methanol masers known to appear in shocked gas, supporting the cloud-cloud collision scenario. From the maser emission we provide constraints on the gas kinetic temperatures (∼30-150 K) and H2 densities (104-105 cm-2). These properties are similar to those found for the starburst galaxy NGC253 also using class I methanol masers, suggested to be associated with a cloud-cloud collision. We conclude that shocks driven by the possible cloud-cloud collision is likely the most important mechanism responsible for the high level of chemical complexity observed in G+0.693-0.03.
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Affiliation(s)
- S. Zeng
- School of Physics and Astronomy, Queen Mary University of London, Mile End Road, E1 4NS London, UK
- Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
- Star and Planet Formation Laboratory, RIKEN Cluster for Pioneering Research, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan
| | - Q. Zhang
- Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
| | - I. Jiménez-Serra
- Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir, Km. 4, Torrejón de Ardoz, 28850 Madrid, Spain
| | - B. Tercero
- Observatorio Astroóomico Nacional (OAN-IGN), Calle Alfonso XII, 3, 28014 Madrid, Spain
- Observatorio de Yebes (IGN), Cerro de la Palera S/N, 19141, Guadalajara, Spain
| | - X. Lu
- National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo, 181-8588, Japan
| | - J. Martín-Pintado
- Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir, Km. 4, Torrejón de Ardoz, 28850 Madrid, Spain
| | - P. de Vicente
- Observatorio de Yebes (IGN), Cerro de la Palera S/N, 19141, Guadalajara, Spain
| | - V. M. Rivilla
- INAF-Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125, Florence, Italy
| | - S. Li
- Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
- Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030, China
- University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing 100049, China
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Cernicharo J, Marcelino N, Agúndez M, Bermúdez C, Cabezas C, Tercero B, Pardo JR. Discovery of HC 4NC in TMC-1: A study of the isomers of HC 3N, HC 5N, and HC 7N. Astron Astrophys 2020; 642:L8. [PMID: 33239824 PMCID: PMC7116413 DOI: 10.1051/0004-6361/202039274] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We present a study of the isocyano isomers of the cyanopolyynes HC3N, HC5N, and HC7N in TMC-1 and IRC+10216 carried out with the Yebes 40m radio telescope. This study has enabled us to report the detection, for the first time in space, of HCCCCNC in TMC-1 and to give upper limits for HC6NC in the same source. In addition, the deuterated isotopologues of HCCNC and HNCCC were detected, along with all 13C substitutions of HCCNC, also for the first time in space. The abundance ratios of HC3N and HC5N, with their isomers, are very different in TMC-1 and IRC+10216, namely, N(HC5N)/N(HC4NC) is ~300 and ≥2100, respectively. We discuss the chemistry of the metastable isomers of cyanopolyynes in terms of the most likely formation pathways and by comparing observational abundance ratios between different sources.
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Affiliation(s)
- J. Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - N. Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - M. Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - C. Bermúdez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - C. Cabezas
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - B. Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (OAN, IGN), Madrid, Spain
| | - J. R. Pardo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
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Cernicharo J, Marcelino N, Agúndez M, Endo Y, Cabezas C, Bermúdez C, Tercero B, de Vicente P. Discovery of HC 3O + in space: The chemistry of O-bearing species in TMC-1. Astron Astrophys 2020; 642:L17. [PMID: 33239825 PMCID: PMC7116414 DOI: 10.1051/0004-6361/202039351] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Using the Yebes 40m and IRAM 30m radio telescopes, we detected a series of harmonically related lines with a rotational constant B 0=4460.590±0.001 MHz and a distortion constant D 0=0.511 ±0.005 kHz towards the cold dense core TMC-1. High-level-of-theory ab initio calculations indicate that the best possible candidate is protonated tricarbon monoxide, HC3O+. We have succeeded in producing this species in the laboratory and observed its J u -J l = 2-1 and 3-2 rotational transitions. Hence, we report the discovery of HC3O+ in space based on our observations, theoretical calculations, and laboratory experiments. We derive an abundance ratio N(C3O)/N(HC3O+)~7. The high abundance of the protonated form of C3O is due to the high proton affinity of the neutral species. The chemistry of O-bearing species is modelled, and predictions are compared to the derived abundances from our data for the most prominent O-bearing species in TMC-1.
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Affiliation(s)
- J Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - N Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - M Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - Y Endo
- Department of Applied Chemistry, Science Building II, National Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan
| | - C Cabezas
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - C Bermúdez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - B Tercero
- Observatorio Astronómico Nacional (IGN), C/ Alfonso XII, 3, 28014, Madrid, Spain
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - P de Vicente
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
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Cernicharo J, Marcelino N, Pardo JR, Agúndez M, Tercero B, de Vicente P, Cabezas C, Bermúdez C. Interstellar nitrile anions: Detection of C 3N - and C 5N - in TMC-1 . Astron Astrophys 2020; 641:L9. [PMID: 33173234 PMCID: PMC7116340 DOI: 10.1051/0004-6361/202039231] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We report on the first detection of C3N- and C5N- towards the cold dark core TMC-1 in the Taurus region, using the Yebes 40 m telescope. The observed C3N/C3N- and C5N/C5N- abundance ratios are ~140 and ~2, respectively; that is similar to those found in the circumstellar envelope of the carbon-rich star IRC +10216. Although the formation mechanisms for the neutrals are different in interstellar (ion-neutral reactions) and circumstellar clouds (photodissociation and radical-neutral reactions), the similarity of the C3N/C3N- and C5N/C5N- abundance ratios strongly suggests a common chemical path for the formation of these anions in interstellar and circumstellar clouds. We discuss the role of radiative electronic attachment, reactions between N atoms and carbon chain anions C n -, and that of H- reactions with HC3N and HC5N as possible routes to form C n N-. The detection of C5N- in TMC-1 gives strong support for assigning to this anion the lines found in IRC +10216, as it excludes the possibility of a metal-bearing species, or a vibrationally excited state. New sets of rotational parameters have been derived from the observed frequencies in TMC-1 and IRC +10216 for C5N- and the neutral radical C5N.
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Affiliation(s)
- J Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - N Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - J R Pardo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - M Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - B Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (IGN), C/ Alfonso XII, 3, 28014, Madrid, Spain
| | - P de Vicente
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - C Cabezas
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - C Bermúdez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
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21
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Pardo JR, Bermúdez C, Cabezas C, Agúndez M, Gallego JD, Fonfría JP, Velilla-Prieto L, Quintana-Lacaci G, Tercero B, Guélin M, Cernicharo J. Detection of vibrationally excited HC 7N and HC 9N in IRC+10216 ⋆. Astron Astrophys 2020; 640:L13. [PMID: 33173233 PMCID: PMC7116341 DOI: 10.1051/0004-6361/202038571] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Observations of IRC +10216 with the Yebes 40m telescope between 31 and 50 GHz have revealed more than 150 unidentified lines. Some of them can be grouped into a new series of 26 doublets, harmonically related with integer quantum numbers ranging from J up=54 to 80. The separation of the doublets increases systematically with J, i.e., as expected for a linear species in one of its bending modes. The rotational parameters resulting from the fit to these data are B = 290.8844 ± 0.0004 MHz, D = 0.88 ± 0.04 Hz, q = 0.1463 ± 0.0001 MHz. The rotational constant is very close to that of the ground state of HC9N. Ab initio calculations show an excellent agreement between these parameters and those predicted for the lowest energy vibrationally excited state, ν 19=1, of HC9N. This is the first detection, and complete characterization in space, of vibrationally excited HC9N. An energy of 41.5 cm-1 is estimated for the ν 19 state. In addition, 17 doublets of HC7N in the ν 15=1 state, for which laboratory spectroscopy is available, have been detected for the first time in IRC+10216. Several doublets of HC5N in its ν 11=1 state have been also observed. The column density ratio between the ground and the lowest excited vibrational states are ≈127, 9.5, and 1.5 for HC5N, HC7N, and HC9N, respectively. We find that these lowest-lying vibrational states are most probably populated via infrared pumping to vibrationally excited states lying at ≈600 cm-1. The lowest vibrationally excited states thus need to be taken into account to precisely determine absolute abundances and abundanceratios for long carbon chains. The abundance ratios N(HC5N)/N(HC7N) and N(HC7N)/N(HC9N) are 2.4 and 7.7 respectively.
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Affiliation(s)
- J. R. Pardo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - C. Bermúdez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - C. Cabezas
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - M. Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - J. D. Gallego
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J. P. Fonfría
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - L. Velilla-Prieto
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
- Dept. of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, 439 92 Onsala, Sweden
| | - G. Quintana-Lacaci
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - B. Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (OAN, IGN), Madrid, Spain
| | - M. Guélin
- Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, F-38406, Saint Martin d’Hères, France
| | - J. Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
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22
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Cabezas C, Bermúdez C, Tercero B, Cernicharo J. The millimeter-wave spectrum and astronomical search for ethyl methyl sulfide. Astron Astrophys 2020; 639:A129. [PMID: 32724240 PMCID: PMC7115819 DOI: 10.1051/0004-6361/202038177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
CONTEXT Sulfur-containing molecules constitute only 8% of the molecules observed in the interstellar medium (ISM), in spite of the fact that sulfur has been shown to be an abundant element in the ISM. In order to understand the chemical behavior of the ISM and specific cases like the missing sulfur reservoir, a detailed chemical molecular composition in the ISM must be mapped out. AIMS Our goal is to investigate the rotational spectrum of ethyl methyl sulfide, CH3CH2SCH3, which ms to be a potential candidate for observation in the ISM since the simpler analogs, CH3SH and CH3CH2SH, have already been detected. Rotational spectrum of ethyl methyl sulfide has been observed before, but its experimental rotational parameters are not precise enough to allow its detection in the ISM. METHODS The rotational spectrum of ethyl methyl sulfide in the frequency range 72-116.5 GHz was measured using a broadband millimeter-wave spectrometer based on radio astronomy receivers with fast Fourier transform backends. The spectral searches and identification of the vibrational excited states of ethyl methyl sulfide was supported by high-level ab initio calculations on the harmonic and anharmonic force fields. RESULTS The rotational spectra for the trans and gauche conformers of ethyl methyl sulfide was analyzed, and a total of 172 and 259 rotational transitions were observed for each one, respectively. The observation of A - E internal rotation splittings allowed the experimental determination of the V 3 hindered internal rotation barrier height for both trans and gauche species. In addition, the vibrational excited states, resulting from the lowest frequency vibrational mode ν 30 were identified for both conformers. The new experimental rotational parameters were employed to search for ethyl methyl sulfide in the warm and cold molecular clouds Orion KL, Sgr B2(N), B1-b and TMC-1, using the spectral surveys captured by IRAM 30 m at 3 mm and 2 mm.
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Affiliation(s)
- C. Cabezas
- Instituto de Física Fundamental (IFF-CSIC). Group of Molecular Astrophysics, C/Serrano 123, 28006 Madrid, Spain
| | - C. Bermúdez
- Instituto de Física Fundamental (IFF-CSIC). Group of Molecular Astrophysics, C/Serrano 123, 28006 Madrid, Spain
| | - B. Tercero
- Observatorio de Yebes (IGN), Cerro de la Palera s/n, 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (OAN-IGN), C/Alfonso XII 3, 28014 Madrid, Spain
| | - J. Cernicharo
- Instituto de Física Fundamental (IFF-CSIC). Group of Molecular Astrophysics, C/Serrano 123, 28006 Madrid, Spain
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Navarro-Almaida D, Le Gal R, Fuente A, Rivière-Marichalar P, Wakelam V, Cazaux S, Caselli P, Laas JC, Alonso-Albi T, Loison JC, Gerin M, Kramer C, Roueff E, Bachiller R, Commerçon B, Friesen R, García-Burillo S, Goicoechea JR, Giuliano BM, Jiménez-Serra I, Kirk JM, Lattanzi V, Malinen J, Marcelino N, Martín-Domènech R, Muñoz Caro GM, Pineda J, Tercero B, Treviño-Morales SP, Roncero O, Hacar A, Tafalla M, Ward-Thompson D. Gas phase Elemental abundances in Molecular cloudS (GEMS) II. On the quest for the sulphur reservoir in molecular clouds: the H 2S case. Astron Astrophys 2020; 637:A39. [PMID: 32565548 PMCID: PMC7305024 DOI: 10.1051/0004-6361/201937180] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
CONTEXT Sulphur is one of the most abundant elements in the Universe. Surprisingly, sulphuretted molecules are not as abundant as expected in the interstellar medium and the identity of the main sulphur reservoir is still an open question. AIMS Our goal is to investigate the H2S chemistry in dark clouds, as this stable molecule is a potential sulphur reservoir. METHODS Using millimeter observations of CS, SO, H2S, and their isotopologues, we determine the physical conditions and H2S abundances along the cores TMC 1-C, TMC 1-CP, and Barnard 1b. The gas-grain model Nautilus is used to model the sulphur chemistry and explore the impact of photo-desorption and chemical desorption on the H2S abundance. RESULTS Our modeling shows that chemical desorption is the main source of gas-phase H2S in dark cores. The measured H2S abundance can only be fitted if we assume that the chemical desorption rate decreases by more than a factor of 10 when n H > 2 × 104. This change in the desorption rate is consistent with the formation of thick H2O and CO ice mantles on grain surfaces. The observed SO and H2S abundances are in good agreement with our predictions adopting an undepleted value of the sulphur abundance. However, the CS abundance is overestimated by a factor of 5 - 10. Along the three cores, atomic S is predicted to be the main sulphur reservoir. CONCLUSIONS The gaseous H2S abundance is well reproduced, assuming undepleted sulphur abundance and chemical desorption as the main source of H2S. The behavior of the observed H2S abundance suggests a changing desorption efficiency, which would probe the snowline in these cold cores. Our model, however, highly overestimates the observed gas-phase CS abundance. Given the uncertainty in the sulphur chemistry, we can only conclude that our data are consistent with a cosmic elemental S abundance with an uncertainty of a factor of 10.
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Affiliation(s)
- D Navarro-Almaida
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - R Le Gal
- Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USA
| | - A Fuente
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | | | - V Wakelam
- Laboratoire d'Astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, allée Geoffroy Saint-Hilaire, 33615 Pessac, France
| | - S Cazaux
- Faculty of Aerospace Engineering, Delft University of Technology, Delft, The Netherlands; University of Leiden, P.O. Box 9513, NL, 2300 RA, Leiden, The Netherlands
| | - P Caselli
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - Jacob C Laas
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - T Alonso-Albi
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - J C Loison
- Institut des Sciences Moléculaires (ISM), CNRS, Univ. Bordeaux, 351 cours de la Libération, F-33400, Talence, France
| | - M Gerin
- Observatoire de Paris, PSL Research University, CNRS, École Normale Supérieure, Sorbonne Universités, UPMC Univ. Paris 06, 75005, Paris, France
| | - C Kramer
- Instituto Radioastronomía Milimétrica (IRAM), Av. Divina Pastora 7, Nucleo Central, 18012, Granada, Spain
| | - E Roueff
- Sorbonne Université, Observatoire de Paris, Université PSL, CNRS, LERMA, F-92190, Meudon, France
| | - R Bachiller
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - B Commerçon
- École Normale Supérieure de Lyon, CRAL, UMR CNRS 5574, Université Lyon I, 46 Allée d'Italie, 69364, Lyon Cedex 07, France
| | - R Friesen
- National Radio Astronomy Observatory, 520 Edgemont Rd., Charlottesville VA USA 22901
| | - S García-Burillo
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - J R Goicoechea
- Instituto de Física Fundamental (CSIC), Calle Serrano 123, 28006, Madrid, Spain
| | - B M Giuliano
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - I Jiménez-Serra
- Centro de Astrobiología (CSIC-INTA), Ctra. de Ajalvir, km 4, Torrejón de Ardoz, 28850, Madrid, Spain
| | - J M Kirk
- Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE, UK
| | - V Lattanzi
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - J Malinen
- Department of Physics, University of Helsinki, PO Box 64, 00014, Helsinki, Finland
- Institute of Physics I, University of Cologne, Cologne, Germany
| | - N Marcelino
- Instituto de Física Fundamental (CSIC), Calle Serrano 123, 28006, Madrid, Spain
| | - R Martín-Domènech
- Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USA
| | - G M Muñoz Caro
- Centro de Astrobiología (CSIC-INTA), Ctra. de Ajalvir, km 4, Torrejón de Ardoz, 28850, Madrid, Spain
| | - J Pineda
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - B Tercero
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - S P Treviño-Morales
- Chalmers University of Technology, Department of Space, Earth and Environment, SE-412 93 Gothenburg, Sweden
| | - O Roncero
- Instituto de Física Fundamental (CSIC), Calle Serrano 123, 28006, Madrid, Spain
| | - A Hacar
- Leiden Observatory, Leiden University, PO Box 9513, 2300-RA, Leiden, The Netherlands
| | - M Tafalla
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - D Ward-Thompson
- Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE, UK
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Abstract
We present the first detections of CH3SH, C3H+, C3N, HCOOH, CH2CHCN, and H2CN in an extragalactic source. Namely the spiral arm of a galaxy located at z = 0.89 on the line of sight to the radio-loud quasar PKS 1830-211. OCS, SO2, and NH2CN were also detected, raising the total number of molecular species identified in that early time galaxy to 54, not counting isotopologues. The detections were made in absorption against the SW quasar image, at 2 kpc from the galaxy centre, over the course of a Q band spectral line survey made with the Yebes 40 m telescope (rest-frame frequencies: 58.7-93.5 GHz). We derived the rotational temperatures and column densities of those species, which are found to be subthermally excited. The molecular abundances, and in particular the large abundances of C3H+ and of several previously reported cations, are characteristic of diffuse or translucent clouds with enhanced UV radiation or strong shocks.
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Affiliation(s)
- B Tercero
- Observatorio Astronómico Nacional (OAN-IGN). Calle Alfonso XII, 3, E-28014 Madrid, Spain
- Observatorio de Yebes (IGN). Cerro de la Palera s/n, E-19141 Yebes, Guadalajara, Spain
| | - J Cernicharo
- Instituto de Física Fundamental (IFF-CSIC). Calle Serrano 123, E-28006 Madrid, Spain
| | - S Cuadrado
- Instituto de Física Fundamental (IFF-CSIC). Calle Serrano 123, E-28006 Madrid, Spain
| | - P de Vicente
- Observatorio de Yebes (IGN). Cerro de la Palera s/n, E-19141 Yebes, Guadalajara, Spain
| | - M Guélin
- Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, 38406 Saint Martin d'Hères, France
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Abstract
CONTEXT Nitriles constitute almost 15% of the molecules observed in the interstellar medium (ISM), surprisingly only two dinitriles have been detected in the ISM so far. The lack of astronomical detections for dinitriles may be partly explained by the absence of laboratory rotational spectroscopic data. AIMS Our goal is to investigate the rotational spectrum of glutaronitrile, N≡C-CH2-CH2-CH2-C≡N, in order to allow its possible detection in the ISM. METHODS The rotational spectrum of glutaronitrile was measured using two different experimental setups. A Fourier transform microwave spectrometer was employed to observe the supersonic jet rotational spectrum of glutaronitrile between 6 and 20 GHz. In addition, the mmW spectrum was observed in the frequency range 72-116.5 GHz using a broadband millimetre-wave spectrometer based on radio astronomy receivers with fast Fourier transform backends. The spectral searches were supported by high-level ab initio calculations. RESULTS A total of 111 rotational transitions with maximum values of J and Ka quantum numbers 54 and 18, respectively, were measured for the gg conformer of glutaronitrile. The analysis allowed us to accurately determine the rotational, nuclear quadrupole coupling, quartic and sextic centrifugal distortion constants. These rotational parameters were employed to search for glutaronitrile in the cold and warm molecular clouds Orion KL, Sgr B2(N), B1-b and TMC-1, using the spectral surveys captured by IRAM 30m at 3mm. Glutaronitrile was not detected, and the upper limits' column densities were derived. Those are a factor of 1.5 and 5 lower than those obtained for the total column densities of the analogous succinonitrile in Orion KL and Sgr B2, respectively.
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Affiliation(s)
- C. Cabezas
- Instituto de Física Fundamental (Iff-CSIC). Group of Molecular Astrophysics, C/ Serrano 123, 28006 Madrid, Spain
| | - C. Bermúdez
- Instituto de Física Fundamental (Iff-CSIC). Group of Molecular Astrophysics, C/ Serrano 123, 28006 Madrid, Spain
| | - Y. Endo
- Department of Applied Chemistry, Science Building II, National Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan
| | - B. Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (OAN-IGN), C/ Alfonso XII 3, 28014 Madrid, Spain
| | - J. Cernicharo
- Instituto de Física Fundamental (Iff-CSIC). Group of Molecular Astrophysics, C/ Serrano 123, 28006 Madrid, Spain
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Cabezas C, Bermúdez C, Gallego JD, Tercero B, Hernández JM, Tanarro I, Herrero VJ, Doménech JL, Cernicharo J. The millimeter-wave spectrum and astronomical search of succinonitrile and its vibrational excited states ★. Astron Astrophys 2019; 629:A35. [PMID: 31485081 PMCID: PMC6726483 DOI: 10.1051/0004-6361/201935899] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
CONTEXT Dinitriles with a saturated hydrocarbon skeleton and a -C≡N group at each end can have large electric dipole moments. Their formation can be related to highly reactive radicals such as CH2CN, C2N or CN. Thus, these saturated dinitriles are potential candidates to be observed in the ISM. AIMS Our goal is the investigation of the rotational spectrum of one of the simplest dinitriles N≡C-CH2-CH2-C≡N, succinonitrile, whose actual rotational parameters are not precise enough to allow its detection in the ISM. In addition, the rotational spectra for its vibrational exicted states will be analyzed. METHODS The rotational spectra of succinonitrile was measured in the frequency range 72-116.5 GHz using a new broadband millimeter-wave spectrometer based on radio astronomy receivers with Fast Fourier Transform backends. The identification of the vibrational excited states of succinonitrile was supported by high-level ab initio calculations on the harmonic and anharmonic force fields. RESULTS A total of 459 rotational transitions with maximum values of J and Ka quantum numbers 70 and 14, respectively, were measured for the ground vibrational state of succinonitrile. The analysis allowed us to accurately determine the rotational, quartic and sextic centrifugal distortion constants. Up to eleven vibrational excited states, resulting from the four lowest frequency vibrational modes ν 13, ν 12, ν 24 and ν 23 were identified. In addition to the four fundamental modes, we observed overtones together with some combination states. The rotational parameters for the ground state were employed to unsuccessfully search for succinonitrile in the cold and warm molecular clouds Orion KL, Sgr B2(N), B1-b and TMC-1, using the spectral surveys captured by IRAM 30m at 3mm and the Yebes 40m at 1.3cm and 7mm. CONCLUSIONS
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Affiliation(s)
- C. Cabezas
- Instituto de Física Fundamental (IFF-CSIC). Group of Molecular Astrophysics, C/ Serrano 123, 28006 Madrid, Spain
| | - C. Bermúdez
- Instituto de Física Fundamental (IFF-CSIC). Group of Molecular Astrophysics, C/ Serrano 123, 28006 Madrid, Spain
| | - J. D. Gallego
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - B. Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (OAN-IGN), C/ Alfonso XII 3, 28014 Madrid, Spain
| | - J. M. Hernández
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - I. Tanarro
- Instituto de Estructura de la Materia (IEM-CSIC). Molecular Physics Department. C/Serrano 123, 28006 Madrid, Spain
| | - V. J. Herrero
- Instituto de Estructura de la Materia (IEM-CSIC). Molecular Physics Department. C/Serrano 123, 28006 Madrid, Spain
| | - J. L. Doménech
- Instituto de Estructura de la Materia (IEM-CSIC). Molecular Physics Department. C/Serrano 123, 28006 Madrid, Spain
| | - J. Cernicharo
- Instituto de Física Fundamental (IFF-CSIC). Group of Molecular Astrophysics, C/ Serrano 123, 28006 Madrid, Spain
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Cernicharo J, Gallego JD, López-Pérez JA, Tercero F, Tanarro I, Beltrán F, de Vicente P, Lauwaet K, Alemán B, Moreno E, Herrero VJ, Doménech JL, Ramírez SI, Bermúdez C, Peláez RJ, Patino-Esteban M, López-Fernández I, García-Álvaro S, García-Carreño P, Cabezas C, Malo I, Amils R, Sobrado J, Diez-González C, Hernandéz J, Tercero B, Santoro G, Martínez L, Castellanos M, Vaquero Jiménez B, Pardo JR, Barbas L, López-Fernández J, Aja B, Leuther A, Martín-Gago JA. Broad band high resolution rotational spectroscopy for Laboratory Astrophysics. Astron Astrophys 2019; 626:10.1051/0004-6361/201935197. [PMID: 31186577 PMCID: PMC6557716 DOI: 10.1051/0004-6361/201935197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present a new experimental setup devoted to the study of gas phase molecules and processes using broad band high spectral resolution rotational spectroscopy. A reactor chamber has been equipped with radio receivers similar to those used by radio astronomers to search for molecular emission in space. The whole Q (31.5-50 GHz) and W bands (72-116.5 GHz) are available for rotational spectroscopy observations. The receivers are equipped with 16×2.5 GHz Fast Fourier Transform spectrometers with a spectral resolution of 38.14 kHz allowing the simultaneous observation of the complete Q band and one third of the W band. The whole W band can be observed in three settings in which the Q band is always observed. Species such as CH3CN, OCS, and SO2 are detected, together with many of their isotopologues and vibrationally excited states, in very short observing times. The system permits automatic overnight observations and integration times as long as 2.4×105 seconds have been reached. The chamber is equipped with a radiofrequency source to produce cold plasmas and with four ultraviolet lamps to study photochemical processes. Plasmas of CH4, N2, CH3CN, NH3, O2, and H2, among other species, have been generated and the molecular products easily identified by their rotational spectrum, and mass spectrometry and optical spectroscopy. Finally, the rotational spectrum of the lowest energy conformer of CH3CH2NHCHO (N-Ethylformamide), a molecule previously characterized in microwave rotational spectroscopy, has been measured up to 116.5 GHz allowing the accurate determination of its rotational and distortion constants and its search in space.
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Affiliation(s)
- J. Cernicharo
- Instituto de Física Fundamental (IFF. CSIC). Group of Molecular Astrophysics, C/Serrano 123, 28006 Madrid, Spain
| | - J. D. Gallego
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J. A. López-Pérez
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - F. Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - I. Tanarro
- Instituto de Estructura de la Materia (IEM. CSIC). Molecular Physics Department. C/Serrano 123, 28006 Madrid, Spain
| | - F. Beltrán
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - P. de Vicente
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - K. Lauwaet
- Instituto de Ciencia de Materiales de Madrid (ICMM. CSIC). Materials Science Factory. Structure of Nanoscopic Systems Group, ESISNA. C/Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Madrid, Spain
- IMDEA Nanociencia, Ciudad Universitaria de Cantoblanco, 28049 Cantoblanco, Madrid, Spain
| | - B. Alemán
- Instituto de Ciencia de Materiales de Madrid (ICMM. CSIC). Materials Science Factory. Structure of Nanoscopic Systems Group, ESISNA. C/Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Madrid, Spain
- IMDEA Materiales, C/Eric Kandel 2, Tecnogetafe, 28906 Getafe, Madrid, Spain
| | - E. Moreno
- Instituto de Física Fundamental (IFF. CSIC). Group of Molecular Astrophysics, C/Serrano 123, 28006 Madrid, Spain
| | - V. J. Herrero
- Instituto de Estructura de la Materia (IEM. CSIC). Molecular Physics Department. C/Serrano 123, 28006 Madrid, Spain
| | - J. L. Doménech
- Instituto de Estructura de la Materia (IEM. CSIC). Molecular Physics Department. C/Serrano 123, 28006 Madrid, Spain
| | - S. I. Ramírez
- Instituto de Física Fundamental (IFF. CSIC). Group of Molecular Astrophysics, C/Serrano 123, 28006 Madrid, Spain
- Centro de Investigaciones Químicas, UAEM. Av. Universidad, 1001 Col. Chamilpa 62209, Cuernavaca, Morelos Mexico
| | - C. Bermúdez
- Instituto de Física Fundamental (IFF. CSIC). Group of Molecular Astrophysics, C/Serrano 123, 28006 Madrid, Spain
| | - R. J. Peláez
- Instituto de Estructura de la Materia (IEM. CSIC). Molecular Physics Department. C/Serrano 123, 28006 Madrid, Spain
| | - M. Patino-Esteban
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - I. López-Fernández
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - S. García-Álvaro
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - P. García-Carreño
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - C. Cabezas
- Instituto de Física Fundamental (IFF. CSIC). Group of Molecular Astrophysics, C/Serrano 123, 28006 Madrid, Spain
| | - I. Malo
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - R. Amils
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J. Sobrado
- Centro de Astrobiología (CSIC-INTA), Crta. de Torrejón de Ardoz a Ajalvir, km 4. Torrejón de Ardoz, 28850, Spain
| | - C. Diez-González
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J.M. Hernandéz
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - B. Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - G. Santoro
- Instituto de Ciencia de Materiales de Madrid (ICMM. CSIC). Materials Science Factory. Structure of Nanoscopic Systems Group, ESISNA. C/Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Madrid, Spain
| | - L. Martínez
- Instituto de Ciencia de Materiales de Madrid (ICMM. CSIC). Materials Science Factory. Structure of Nanoscopic Systems Group, ESISNA. C/Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Madrid, Spain
| | - M. Castellanos
- Instituto de Física Fundamental (IFF. CSIC). Group of Molecular Astrophysics, C/Serrano 123, 28006 Madrid, Spain
| | - B. Vaquero Jiménez
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J. R. Pardo
- Instituto de Física Fundamental (IFF. CSIC). Group of Molecular Astrophysics, C/Serrano 123, 28006 Madrid, Spain
| | - L. Barbas
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J.A. López-Fernández
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - B. Aja
- Universidad de Cantabria, Department of Communication Engineering, Avda. Los Castros, 39005 Santander, Spain
| | - A. Leuther
- Fraunhofer Institut fur Angewandte Festkorperphysik, Tullastresse 72, 79108 Freiburg, Germany
| | - J. A. Martín-Gago
- Instituto de Ciencia de Materiales de Madrid (ICMM. CSIC). Materials Science Factory. Structure of Nanoscopic Systems Group, ESISNA. C/Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Madrid, Spain
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Fuente A, Navarro DG, Caselli P, Gerin M, Kramer C, Roueff E, Alonso-Albi T, Bachiller R, Cazaux S, Commercon B, Friesen R, García-Burillo S, Giuliano BM, Goicoechea JR, Gratier P, Hacar A, Jiménez-Serra I, Kirk J, Lattanzi V, Loison JC, Malinen J, Marcelino N, Martín-Doménech R, Muñoz-Caro G, Pineda J, Tafalla M, Tercero B, Ward-Thompson D, Treviño-Morales SP, Riviére-Marichalar P, Roncero O, Vidal T, Ballester MY. Gas phase Elemental abundances in Molecular cloudS (GEMS): I. The prototypical dark cloud TMC 1. Astron Astrophys 2019; 624:10.1051/0004-6361/201834654. [PMID: 31156252 PMCID: PMC6542666 DOI: 10.1051/0004-6361/201834654] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
GEMS is an IRAM 30m Large Program whose aim is determining the elemental depletions and the ionization fraction in a set of prototypical star-forming regions. This paper presents the first results from the prototypical dark cloud TMC 1. Extensive millimeter observations have been carried out with the IRAM 30m telescope (3 mm and 2 mm) and the 40m Yebes telescope (1.3 cm and 7 mm) to determine the fractional abundances of CO, HCO+, HCN, CS, SO, HCS+, and N2H+ in three cuts which intersect the dense filament at the well-known positions TMC 1-CP, TMC 1-NH3, and TMC 1-C, covering a visual extinction range from A V ~ 3 to ~20 mag. Two phases with differentiated chemistry can be distinguished: i) the translucent envelope with molecular hydrogen densities of 1-5×103 cm-3; and ii) the dense phase, located at A V > 10 mag, with molecular hydrogen densities >104 cm-3. Observations and modeling show that the gas phase abundances of C and O progressively decrease along the C+/C/CO transition zone (A V ~ 3 mag) where C/H ~ 8×10-5 and C/O~0.8-1, until the beginning of the dense phase at A V ~ 10 mag. This is consistent with the grain temperatures being below the CO evaporation temperature in this region. In the case of sulfur, a strong depletion should occur before the translucent phase where we estimate a S/H ~ (0.4 - 2.2) ×10-6, an abundance ~7-40 times lower than the solar value. A second strong depletion must be present during the formation of the thick icy mantles to achieve the values of S/H measured in the dense cold cores (S/H ~8×10-8). Based on our chemical modeling, we constrain the value of ζ H2 to ~ (0.5 - 1.8) ×10-16 s-1 in the translucent cloud.
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Affiliation(s)
- A Fuente
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - D G Navarro
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - P Caselli
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - M Gerin
- Observatoire de Paris, PSL Research University, CNRS, École Normale Supérieure, Sorbonne Universités, UPMC Univ. Paris 06, 75005, Paris, France
| | - C Kramer
- Instituto Radioastronomía Milimétrica (IRAM), Av. Divina Pastora 7, Nucleo Central, 18012, Granada, Spain
| | - E Roueff
- Sorbonne Université, Observatoire de Paris, Université PSL, CNRS, LERMA, F-92190, Meudon, France
| | - T Alonso-Albi
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - R Bachiller
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - S Cazaux
- Faculty of Aerospace Engineering, Delft University of Technology, Delft, The Netherlands ; University of Leiden, P.O. Box 9513, NL, 2300 RA, Leiden, The Netherlands
| | - B Commercon
- École Normale Supérieure de Lyon, CRAL, UMR CNRS 5574, Université Lyon I, 46 Allée d'Italie, 69364, Lyon Cedex 07, France
| | - R Friesen
- National Radio Astronomy Observatory, 520 Edgemont Rd., Charlottesville VA USA 22901
| | - S García-Burillo
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - B M Giuliano
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - J R Goicoechea
- Instituto de Física Fundamental (CSIC), Calle Serrano 123, 28006, Madrid, Spain
| | - P Gratier
- Laboratoire d'astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, allée Geoffroy Saint-Hilaire, 33615, Pessac, France
| | - A Hacar
- Leiden Observatory, Leiden University, PO Box 9513, 2300-RA, Leiden, The Netherlands
| | - I Jiménez-Serra
- Centro de Astrobiología (CSIC-INTA), Ctra. de Ajalvir, km 4, Torrejón de Ardoz, 28850, Madrid, Spain
| | - J Kirk
- Department of Physics, University of Warwick, Coventry CV4 7AL, UK
| | - V Lattanzi
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - J C Loison
- Institut des Sciences Moléculaires (ISM), CNRS, Univ. Bordeaux, 351 cours de la Libération, F-33400, Talence, France
| | - J Malinen
- Department of Physics, University of Helsinki, PO Box 64, 00014, Helsinki, Finland
- Institute of Physics I, University of Cologne, Cologne, Germany
| | - N Marcelino
- Instituto de Física Fundamental (CSIC), Calle Serrano 123, 28006, Madrid, Spain
| | - R Martín-Doménech
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA
| | - G Muñoz-Caro
- Centro de Astrobiología (CSIC-INTA), Ctra. de Ajalvir, km 4, Torrejón de Ardoz, 28850, Madrid, Spain
| | - J Pineda
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - M Tafalla
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - B Tercero
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - D Ward-Thompson
- Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE, UK
| | - S P Treviño-Morales
- Chalmers University of Technology, Department of Space, Earth and Environment, SE-412 93 Gothenburg, Sweden
| | | | - O Roncero
- Instituto de Física Fundamental (CSIC), Calle Serrano 123, 28006, Madrid, Spain
| | - T Vidal
- Laboratoire d'astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, allée Geoffroy Saint-Hilaire, 33615, Pessac, France
| | - Maikel Y Ballester
- Departamento de Física, Universidade Federal de Juiz de Fora-UFJF, Juiz de Fora, MG 36036-330, Brazil
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Tercero B, Cuadrado S, López A, Brouillet N, Despois D, Cernicharo J. Chemical segregation of complex organic O-bearing species in Orion KL. Astron Astrophys 2018; 620:L6. [PMID: 31031406 PMCID: PMC6485672 DOI: 10.1051/0004-6361/201834417] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We investigate the chemical segregation of complex O-bearing species (including the largest and most complex ones detected to date in space) towards Orion KL, the closest high-mass star-forming region. The molecular line images obtained using the ALMA science verification data reveal a clear segregation of chemically related species depending on their different functional groups. We map the emission of 13CH3OH, HCOOCH3, CH3OCH3, CH2OCH2, CH3COOCH3, HCOOCH2CH3, CH3CH2OCH3, HCOOH, OHCH2CH2OH, CH3COOH, CH3CH2OH, CH3OCH2OH, OHCH2CHO, and CH3COCH3 with ~1.5″ angular resolution and provide molecular abundances of these species toward different gas components of this region. We disentangle the emission of these species in the different Orion components by carefully selecting lines free of blending and opacity effects. Possible effects in the molecular spatial distribution due to residual blendings and different excitation conditions are also addressed. We find that while species containing the C-O-C group, i.e. an ether group, exhibit their peak emission and higher abundance towards the compact ridge, the hot core south is the component where species containing a hydroxyl group (-OH) bound to a carbon atom (C-O-H) present their emission peak and higher abundance. This finding allows us to propose methoxy (CH3O-) and hydroxymethyl (-CH2OH) radicals as the major drivers of the chemistry in the compact ridge and the hot core south, respectively, as well as different evolutionary stages and prevailing physical processes in the different Orion components.
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Affiliation(s)
- B Tercero
- Observatorio Astronómico Nacional (OAN-IGN). Calle Alfonso XII, 3, E-28014 Madrid, Spain
| | - S Cuadrado
- Instituto de Física Fundamental (IFF-CSIC). Calle Serrano 123, E-28006 Madrid, Spain
| | - A López
- Instituto de Física Fundamental (IFF-CSIC). Calle Serrano 123, E-28006 Madrid, Spain
| | - N Brouillet
- Laboratoire d'astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, alle Geoffroy Saint-Hilaire, 33615 Pessac, France
| | - D Despois
- Laboratoire d'astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, alle Geoffroy Saint-Hilaire, 33615 Pessac, France
| | - J Cernicharo
- Instituto de Física Fundamental (IFF-CSIC). Calle Serrano 123, E-28006 Madrid, Spain
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30
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Bermúdez C, Tercero B, Motiyenko RA, Margulès L, Cernicharo J, Ellinger Y, Guillemin JC. The millimeter-wave spectrum of methyl ketene and the astronomical search for it. Astron Astrophys 2018; 619:A92. [PMID: 30595605 PMCID: PMC6309256 DOI: 10.1051/0004-6361/201833267] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
CONTEXT The analysis of isomeric species of a compound observed in the interstellar medium (ISM) is a useful tool to understand the chemistry of complex organic molecules. It could, likewise, assist in the detection of new species. AIMS Our goal consists in analyzing one of the two most stable species of the C3H4O family, methyl ketene, whose actual rotational parameters are not precise enough to allow its detection in the ISM. The obtained parameters will be used to search for it in the high-mass star-forming regions Orion KL and Sagittarius B2, as well as in the cold dark clouds TMC-1 in the Taurus Molecular Cloud and Barnard 1 (B1-b). METHODS A millimeter-wave room-temperature rotational spectrum of methyl ketene was recorded from 50 to 330 GHz. The internal rotation analysis of its ground state and first torsional excited state was performed with the rho-axis method employing the RAM36 program. RESULTS More than 3000 transitions of the rotational spectrum of the ground state (Kamax = 18) and first torsional excited state (Kamax = 13) of methyl ketene were fitted using a Hamiltonian that contains 41 parameters with an RMS (root mean square) of 41 kHz. Column density limits were calculated but no lines were detected in the ISM belonging to methyl ketene.
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Affiliation(s)
- C Bermúdez
- Université de Lille, Faculté des Sciences et Technologies, Département Physique, Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, 59655 Villeneuve d'Ascq Cedex, France
| | - B Tercero
- Observatorio Astronómico Nacional (IGN), C/Alfonso XII 3, 28014 Madrid, Spain
| | - R A Motiyenko
- Université de Lille, Faculté des Sciences et Technologies, Département Physique, Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, 59655 Villeneuve d'Ascq Cedex, France
| | - L Margulès
- Université de Lille, Faculté des Sciences et Technologies, Département Physique, Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, 59655 Villeneuve d'Ascq Cedex, France
| | - J Cernicharo
- Instituto de Física Fundamental, Dpt. of Molecular Astrophysics, CSIC, C/ Serrano 121, 28006, Madrid, Spain
| | - Y Ellinger
- Sorbone Université, CNRS, Laboratoire de Chimie Théorique, LCT, F. 75005 Paris, France
| | - J-C Guillemin
- Univ. Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR - UMR6226, F-35000 Rennes, France
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Kolesniková L, Peña I, Alonso ER, Tercero B, Cernicharo J, Mata S, Alonso JL. Laboratory rotational spectrum and astronomical search for methoxyacetaldehyde. Astron Astrophys 2018; 619:A67. [PMID: 30555173 PMCID: PMC6290985 DOI: 10.1051/0004-6361/201833773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
CONTEXT Methoxyacetaldehyde belongs to a group of structural isomers with the general formula C3H6O2, of which methyl acetate and ethyl formate are known interstellar molecules. Rotational data available for methoxyacetaldehyde are limited to 40 GHz, which makes predictions at higher frequencies rather uncertain. AIMS The aim of this work is to provide accurate experimental frequencies of methoxyacetaldehyde in the millimeter-wave region to support its detection in the interstellar medium. METHODS The rotational spectrum of methoxyacetaldehyde was recorded at room-temperature from 75 to 120 GHz and from 170 to 310 GHz using the millimeter-wave spectrometer in Valladolid. Additional measurements were also performed at conditions of supersonic expansion from 6 to 18 GHz. The assigned rotational transitions were analyzed using the S -reduced semirigid-rotor Hamiltonian. RESULTS We newly assigned over 1000 lines for the most stable conformer of methoxyacetaldehyde in its ground state and five lowest excited vibrational states, and precise sets of spectroscopic constants were obtained. We searched for spectral features of methoxyacetaldehyde in the high-mass star-forming regions Orion KL and Sagittarius B2, as well as in the cold dark cloud Barnard 1 (B1-b). No lines belonging to methoxyacetaldehyde were detected above the detection limit of our data. We provide upper limits to the methoxyacetaldehyde colum density in these sources.
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Affiliation(s)
- L Kolesniková
- Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain
| | - I Peña
- Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain
| | - E R Alonso
- Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain
| | - B Tercero
- Observatorio Astronómico Nacional (OAN-IGN), Calle Alfonso XII 3, 28014 Madrid, Spain
| | - J Cernicharo
- Instituto de Física Fundamental (IFF-CSIC), Calle Serrano 123, 28006 Madrid, Spain
| | - S Mata
- Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain
| | - J L Alonso
- Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain
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Kolesniková L, Alonso ER, Tercero B, Cernicharo J, Alonso JL. Millimeter wave spectra of ethyl isocyanate and searches for it in Orion KL and Sgr B2. Astron Astrophys 2018; 616:A173. [PMID: 30369619 PMCID: PMC6203308 DOI: 10.1051/0004-6361/201833223] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
CONTEXT Relatively high abundances of methyl isocyanate (CH3NCO), a methyl derivative of isocyanic acid (HNCO), found in the Orion KL and Sgr B2 molecular clouds suggest that its ethyl derivative, ethyl isocyanate (CH3CH2NCO), may also be present. AIMS The aim of this work is to provide accurate experimental frequencies of ethyl isocyanate in its ground and excited vibrational states in the millimeter wave region to support searches for it in the interstellar medium. METHODS The rotational spectrum of ethyl isocyanate was recorded at room temperature from 80 to 340 GHz using the millimeter wave spectrometer in Valladolid. Assigned rotational transitions were analyzed using the S -reduced semirigid-rotor Hamiltonian. RESULTS More than 1100 distinct frequency lines were analyzed for the ground vibrational state of the cis conformer as well as for three vibrational satellites corresponding to successive excitation of the lowest-energy C-N torsional mode. Newly determined rotational and centrifugal distortion constants were used for searches of spectral features of ethyl isocyanate in Orion KL and Sgr B2 clouds. Upper limits to CH3CH2NCO in these high-mass star-forming regions were obtained.
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Affiliation(s)
- L Kolesniková
- Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, E-47011 Valladolid, Spain
| | - E R Alonso
- Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, E-47011 Valladolid, Spain
| | - B Tercero
- Observatorio Astronómico Nacional (OAN-IGN). Calle Alfonso XII, 3, E-28014 Madrid, Spain
| | - J Cernicharo
- Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3,E-28049 Cantoblanco, Spain
| | - J L Alonso
- Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, E-47011 Valladolid, Spain
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Pardo JR, Cernicharo J, Velilla Prieto L, Fonfría JP, Agúndez M, Quintana-Lacaci G, Massalkhi S, Tercero B, Gómez-Garrido M, de Vicente P, Guélin M, Kramer C, Marka C, Teyssier D, Neufeld D. Time-dependent molecular emission in IRC+10216. Astron Astrophys 2018; 615:L4. [PMID: 30185989 PMCID: PMC6120678 DOI: 10.1051/0004-6361/201833303] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
CONTEXT The variability in IRC+10216, the envelope of the asymptotic giant branch (AGB) star CW Leo, has attracted increasing attention in recent years. Studying the details of this variability in the molecular emission required a systematic observation program. AIMS We aim to reveal and characterize the periodical variability of the rotational lines from several molecules and radicals in IRC+10216, and to compare it with previously reported IR variability. METHODS We carried out systematic monitoring within the ~80 to 116 GHz frequency range with the IRAM 30m telescope. RESULTS We report on the periodical variability in IRC+10216 of several rotational lines from the following molecules and radicals: HC3N, HC5N, CCH, C4H, C5H, and CN. The analysis of the variable molecular lines provides periods that are consistent with previously reported IR variability, and interesting phase lags are revealed that point toward radiative transfer and pumping, rather than chemical effects. CONCLUSIONS This study indicates that observations of several lines of a given molecule have to be performed simultaneously or at least at the same phase in order to avoid erroneous interpretation of the data. In particular, merging ALMA data from different epochs may prove to be difficult, as shown by the example of the variability we studied here. Moreover, radiative transfer codes have to incorporate the effect of population variability in the rotational levels in CW Leo.
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Affiliation(s)
- J R Pardo
- Consejo Superior de Investigaciones Científicas, Instituto de Física Fundamental, Serrano 123, 28006 Madrid, Spain
| | - J Cernicharo
- Consejo Superior de Investigaciones Científicas, Instituto de Física Fundamental, Serrano 123, 28006 Madrid, Spain
| | - L Velilla Prieto
- Consejo Superior de Investigaciones Científicas, Instituto de Física Fundamental, Serrano 123, 28006 Madrid, Spain
| | - J P Fonfría
- Consejo Superior de Investigaciones Científicas, Instituto de Física Fundamental, Serrano 123, 28006 Madrid, Spain
| | - M Agúndez
- Consejo Superior de Investigaciones Científicas, Instituto de Física Fundamental, Serrano 123, 28006 Madrid, Spain
| | - G Quintana-Lacaci
- Consejo Superior de Investigaciones Científicas, Instituto de Física Fundamental, Serrano 123, 28006 Madrid, Spain
| | - S Massalkhi
- Consejo Superior de Investigaciones Científicas, Instituto de Física Fundamental, Serrano 123, 28006 Madrid, Spain
| | - B Tercero
- Instituto Geográfico Nacional, Centro de Desarrollos Tecnológicos, Observatorio de Yebes, Apartado 148, 19080 Yebes, Spain
| | - M Gómez-Garrido
- Instituto Geográfico Nacional, Centro de Desarrollos Tecnológicos, Observatorio de Yebes, Apartado 148, 19080 Yebes, Spain
| | - P de Vicente
- Instituto Geográfico Nacional, Centro de Desarrollos Tecnológicos, Observatorio de Yebes, Apartado 148, 19080 Yebes, Spain
| | - M Guélin
- Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, 38406 St-Martin d'Hères, France
| | - C Kramer
- Instituto de Radioastronomía Milimétrica, Av. Divina Pastora 7, Local 20, 18012 Granada, Spain
| | - C Marka
- Instituto de Radioastronomía Milimétrica, Av. Divina Pastora 7, Local 20, 18012 Granada, Spain
| | - D Teyssier
- Herschel Science Centre, ESA/ESAC, P.O. Box 78, Villanueva de la Cañada, Madrid, Spain
| | - D Neufeld
- Department of Physics and Astronomy, John Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
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Cernicharo J, Lefloch B, Agúndez M, Bailleux S, Margulès L, Roueff E, Bachiller R, Marcelino N, Tercero B, Vastel C, Caux E. Discovery of the Ubiquitous Cation NS + in Space Confirmed by Laboratory Spectroscopy. Astrophys J Lett 2018; 853:L22. [PMID: 29983906 PMCID: PMC6031291 DOI: 10.3847/2041-8213/aaa83a] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We report the detection in space of a new molecular species which has been characterized spectroscopically and fully identified from astrophysical data. The observations were carried out with the 30m IRAM telescopea. The molecule is ubiquitous as its J=2→1 transition has been found in cold molecular clouds, prestellar cores, and shocks. However, it is not found in the hot cores of Orion-KL and in the carbon-rich evolved star IRC+10216. Three rotational transitions in perfect harmonic relation J' = 2/3/5 have been identified in the prestellar core B1b. The molecule has a 1Σ electronic ground state and its J=2→1 transition presents the hyperfine structure characteristic of a molecule containing a nucleus with spin 1. A careful analysis of possible carriers shows that the best candidate is NS+. The derived rotational constant agrees within 0.3-0.7% with ab initio calculations. NS+ was also produced in the laboratory to unambiguously validate the astrophysical assignment. The observed rotational frequencies and determined molecular constants confirm the discovery of the nitrogen sulfide cation in space. The chemistry of NS+ and related nitrogen-bearing species has been analyzed by means of a time-dependent gas phase model. The model reproduces well the observed NS/NS+ abundance ratio, in the range 30-50, and indicates that NS+ is formed by reactions of the neutral atoms N and S with the cations SH+ and NH+, respectively.
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Affiliation(s)
- J Cernicharo
- Group of Molecular Astrophysics. ICMM. CSIC. C/Sor Juana Inés de La Cruz 3, E-28049, Madrid, Spain
- Dpt. of Molecular Astrophysics. IFF. CSIC. C/Serrano 123, E-28006, Madrid, Spain
| | - B Lefloch
- Université Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
| | - M Agúndez
- Group of Molecular Astrophysics. ICMM. CSIC. C/Sor Juana Inés de La Cruz 3, E-28049, Madrid, Spain
- Dpt. of Molecular Astrophysics. IFF. CSIC. C/Serrano 123, E-28006, Madrid, Spain
| | - S Bailleux
- Laboratoire de Physique des Lasers, Atomes et Molécules, UMR 8523 CNRS, Université Lille, 59655 Villeneuve d'Ascq Cedex, France
| | - L Margulès
- Laboratoire de Physique des Lasers, Atomes et Molécules, UMR 8523 CNRS, Université Lille, 59655 Villeneuve d'Ascq Cedex, France
| | - E Roueff
- LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universits, UPMC Univ. Paris 06, F-92190 Meudon, France
| | - R Bachiller
- Observatorio Astronómico Nacional (OAN, IGN), Calle Alfonso XII, 3, 28014 Madrid, Spain
| | - N Marcelino
- Group of Molecular Astrophysics. ICMM. CSIC. C/Sor Juana Inés de La Cruz 3, E-28049, Madrid, Spain
- Dpt. of Molecular Astrophysics. IFF. CSIC. C/Serrano 123, E-28006, Madrid, Spain
| | - B Tercero
- Group of Molecular Astrophysics. ICMM. CSIC. C/Sor Juana Inés de La Cruz 3, E-28049, Madrid, Spain
- Observatorio Astronómico Nacional (OAN, IGN), Calle Alfonso XII, 3, 28014 Madrid, Spain
| | - C Vastel
- IRAP, Université de Toulouse, CNRS, UPS, CNES, Toulouse, France
| | - E Caux
- IRAP, Université de Toulouse, CNRS, UPS, CNES, Toulouse, France
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Kolesniková L, Tercero B, Alonso ER, Guillemin JC, Cernicharo J, Alonso JL. Rotational spectrum of methoxyamine up to 480 GHz: a laboratory study and astronomical search. Astron Astrophys 2018; 609:A24. [PMID: 29983447 PMCID: PMC6031297 DOI: 10.1051/0004-6361/201730744] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
AIMS Methoxyamine is a potential interstellar amine that has been predicted by gas-grain chemical models for the formation of complex molecules. The aim of this work is to provide direct experimental frequencies of its ground-vibrational state in the millimeter- and submillimeter-wave regions to achieve its detection in the interstellar medium. METHODS Methoxyamine was chemically liberated from its hydrochloride salt, and its rotational spectrum was recorded at room temperature from 75 to 480 GHz using the millimeter-wave spectrometer in Valladolid. Many observed transitions revealed A-E splitting caused by the internal rotation of the methyl group, which had to be treated with specific internal rotation codes. RESULTS Over 400 lines were newly assigned for the most stable conformer of methoxyamine, and a precise set of spectroscopic constants was obtained. Spectral features of methoxyamine were then searched for in the Orion KL, Sgr B2, B1-b, and TMC-1 molecular clouds. Upper limits to the column density of methoxyamine were derived.
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Affiliation(s)
- L Kolesniková
- Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain
| | - B Tercero
- Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Spain
| | - E R Alonso
- Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain
| | - J-C Guillemin
- Institut des Sciences Chimiques de Rennes, École Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7, France
| | - J Cernicharo
- Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Spain
| | - J L Alonso
- Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain
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Cernicharo J, Agúndez M, Velilla Prieto L, Guélin M, Pardo JR, Kahane C, Marka C, Kramer C, Navarro S, Quintana-Lacaci G, Fonfría JP, Marcelino N, Tercero B, Moreno E, Massalkhi S, Santander-García M, McCarthy MC, Gottlieb CA, Alonso JL. Discovery of methyl silane and confirmation of silyl cyanide in IRC +10216. Astron Astrophys 2017; 606:L5. [PMID: 29142328 PMCID: PMC5683346 DOI: 10.1051/0004-6361/201731672] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We report the discovery in space of methyl silane, CH3SiH3, from observations of ten rotational transitions between 80 and 350 GHz (Ju from 4 to 16) with the IRAM 30 m radio telescope. The molecule was observed in the envelope of the C-star IRC +10216. The observed profiles and our models for the expected emission of methyl silane suggest that the it is formed in the inner zones of the circumstellar envelope, 1-40 R*, with an abundance of (0.5-1) × 10-8 relative to H2. We also observed several rotational transitions of silyl cyanide (SiH3CN), confirming its presence in IRC +10216 in particular, and in space in general. Our models indicate that silyl cyanide is also formed in the inner regions of the envelope, around 20 R*, with an abundance relative to H2 of 6×10-10. The possible formation mechanisms of both species are discussed. We also searched for related chemical species but only upper limits could be obtained.
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Affiliation(s)
- J Cernicharo
- Group of Molecular Astrophysics, ICMM, CSIC, C/ Sor Juana Inés de La Cruz 3, 28049 Madrid, Spain
| | - M Agúndez
- Group of Molecular Astrophysics, ICMM, CSIC, C/ Sor Juana Inés de La Cruz 3, 28049 Madrid, Spain
| | - L Velilla Prieto
- Group of Molecular Astrophysics, ICMM, CSIC, C/ Sor Juana Inés de La Cruz 3, 28049 Madrid, Spain
| | - M Guélin
- Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, 38406 St-Martin d'Hères, France
| | - J R Pardo
- Group of Molecular Astrophysics, ICMM, CSIC, C/ Sor Juana Inés de La Cruz 3, 28049 Madrid, Spain
| | - C Kahane
- Université Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
| | - C Marka
- Instituto de Radioastronomía Milimétrica, Av. Divina Pastora 7, Local 20, 18012 Granada, Spain
| | - C Kramer
- Instituto de Radioastronomía Milimétrica, Av. Divina Pastora 7, Local 20, 18012 Granada, Spain
| | - S Navarro
- Instituto de Radioastronomía Milimétrica, Av. Divina Pastora 7, Local 20, 18012 Granada, Spain
| | - G Quintana-Lacaci
- Group of Molecular Astrophysics, ICMM, CSIC, C/ Sor Juana Inés de La Cruz 3, 28049 Madrid, Spain
| | - J P Fonfría
- Group of Molecular Astrophysics, ICMM, CSIC, C/ Sor Juana Inés de La Cruz 3, 28049 Madrid, Spain
| | - N Marcelino
- Group of Molecular Astrophysics, ICMM, CSIC, C/ Sor Juana Inés de La Cruz 3, 28049 Madrid, Spain
| | - B Tercero
- Group of Molecular Astrophysics, ICMM, CSIC, C/ Sor Juana Inés de La Cruz 3, 28049 Madrid, Spain
| | - E Moreno
- Group of Molecular Astrophysics, ICMM, CSIC, C/ Sor Juana Inés de La Cruz 3, 28049 Madrid, Spain
| | - S Massalkhi
- Group of Molecular Astrophysics, ICMM, CSIC, C/ Sor Juana Inés de La Cruz 3, 28049 Madrid, Spain
| | - M Santander-García
- Group of Molecular Astrophysics, ICMM, CSIC, C/ Sor Juana Inés de La Cruz 3, 28049 Madrid, Spain
| | - M C McCarthy
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, and School of Engineering & Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - C A Gottlieb
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, and School of Engineering & Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - J L Alonso
- Grupo de Espectroscopía Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopía y Bioespectroscopía, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain
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Rizzo JR, Tercero B, Cernicharo J. A spectroscopic survey of Orion KL between 41.5 and 50 GHz. Astron Astrophys 2017; 605:A76. [PMID: 29151606 PMCID: PMC5693341 DOI: 10.1051/0004-6361/201629936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
CONTEXT The nearby massive star-forming region Orion KL is one of the richest molecular reservoirs known in our Galaxy. The region hosts newly formed protostars, and the strong interaction between their radiation and their outflows with the environment results in a series of complex chemical processes leading to a high diversity of interstellar tracers. The region is therefore one of the most frequently observed sources, and the site where many molecular species have been discovered for the first time. AIMS With the availability of powerful wideband backends, it is nowadays possible to complete spectral surveys in the entire mm-range to obtain a spectroscopically unbiased chemical picture of the region. METHODS In this paper we present a sensitive spectral survey of Orion KL, made with one of the 34 m antennas of the Madrid Deep Space Communications Complex in Robledo de Chavela, Spain. The spectral range surveyed is from 41.5 to 50 GHz, with a frequency spacing of 180 kHz (equivalent to ≈ 1.2 km s-1, depending on the exact frequency). The rms achieved ranges from 8 to 12 mK. RESULTS The spectrum is dominated by the J = 1 → 0 SiO maser lines and by radio recombination lines (RRLs), which were detected up to Δn = 11. Above a 3 σ level, we identified 66 RRLs and 161 molecular lines corresponding to 39 isotopologues from 20 molecules; a total of 18 lines remain unidentified, two of them above a 5 σ level. Results of radiative modelling of the detected molecular lines (excluding masers) are presented. CONCLUSIONS At this frequency range, this is the most sensitive survey and also the one with the widest band. Although some complex molecules like CH3CH2CN and CH2CHCN arise from the hot core, most of the detected molecules originate from the low temperature components in Orion KL.
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Affiliation(s)
- J R Rizzo
- Departamento de Astrofísica. Centro de Astrobiología (INTA-CSIC). Ctra. M-108, km. 4, E-28850 Torrejón de Ardoz, Spain
| | - B Tercero
- Grupo de Astrofísica Molecular. Instituto de Ciencia de Materiales de Madrid (CSIC). Calle Sor Juana Inés de la Cruz 3, Cantoblanco, E-28049 Madrid, Spain
| | - J Cernicharo
- Grupo de Astrofísica Molecular. Instituto de Ciencia de Materiales de Madrid (CSIC). Calle Sor Juana Inés de la Cruz 3, Cantoblanco, E-28049 Madrid, Spain
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Abstract
We investigate the presence of complex organic molecules (COMs) in strongly UV-irradiated interstellar molecular gas. We have carried out a complete millimetre (mm) line survey using the IRAM 30 m telescope towards the edge of the Orion Bar photodissociation region (PDR), close to the H2 dissociation front, a position irradiated by a very intense far-UV (FUV) radiation field. These observations have been complemented with 8.5″ resolution maps of the H2CO JKa,Kc = 51,5 → 41,4 and C18O J = 3 → 2 emission at 0.9 mm. Despite being a harsh environment, we detect more than 250 lines from COMs and related precursors: H2CO, CH3OH, HCO, H2CCO, CH3CHO, H2CS, HCOOH, CH3CN, CH2NH, HNCO, [Formula: see text] and HC3N (in decreasing order of abundance). For each species, the large number of detected lines allowed us to accurately constrain their rotational temperatures (Trot) and column densities (N). Owing to subthermal excitation and intricate spectroscopy of some COMs (symmetric- and asymmetric-top molecules such as CH3CN and H2CO, respectively), a correct determination of N and Trot requires building rotational population diagrams of their rotational ladders separately. The inferred column densities are in the 1011 - 1013cm-2 range. We also provide accurate upper limit abundances for chemically related molecules that might have been expected, but are not conclusively detected at the edge of the PDR (HDCO, CH3O, CH3NC, CH3CCH, CH3OCH3, HCOOCH3, CH3CH2OH, CH3CH2CN, and CH2CHCN). A non-thermodynamic equilibrium excitation analysis for molecules with known collisional rate coefficients suggests that some COMs arise from different PDR layers but we cannot resolve them spatially. In particular, H2CO and CH3CN survive in the extended gas directly exposed to the strong FUV flux (Tk = 150 - 250 K and Td ≳ 60 K), whereas CH3OH only arises from denser and cooler gas clumps in the more shielded PDR interior (Tk = 40 - 50 K). The non-detection of HDCO towards the PDR edge is consistent with the minor role of pure gas-phase deuteration at very high temperatures. We find a HCO/H2CO/CH3OH ≃ 1/5/3 abundance ratio. These ratios are different from those inferred in hot cores and shocks. Taking into account the elevated gas and dust temperatures at the edge of the Bar (mostly mantle-free grains), we suggest the following scenarios for the formation of COMs: (i) hot gas-phase reactions not included in current models; (ii) warm grain-surface chemistry; or (iii) the PDR dynamics is such that COMs or precursors formed in cold icy grains deeper inside the molecular cloud desorb and advect into the PDR.
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Affiliation(s)
- S Cuadrado
- Grupo de Astrofísica Molecular. Instituto de Ciencia de Materiales de Madrid (CSIC), Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Madrid, Spain
| | - J R Goicoechea
- Grupo de Astrofísica Molecular. Instituto de Ciencia de Materiales de Madrid (CSIC), Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Madrid, Spain
| | - J Cernicharo
- Grupo de Astrofísica Molecular. Instituto de Ciencia de Materiales de Madrid (CSIC), Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Madrid, Spain
| | - A Fuente
- Observatorio Astronómico Nacional, Apdo. 112, 28803 Alcalá de Henares, Madrid, Spain
| | - J Pety
- Institut de Radioastronomie Millimétrique (IRAM), 300 rue de la Piscine, F-38406 Saint Martin d'Hères, France
- LERMA, Observatoire de Paris, CNRS UMR 8112, École Normale Supérieure, PSL research university, 24 rue Lhomond, 75231, Paris Cedex 05, France
| | - B Tercero
- Grupo de Astrofísica Molecular. Instituto de Ciencia de Materiales de Madrid (CSIC), Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Madrid, Spain
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Abstract
As many organic molecules, formic acid (HCOOH) has two conformers (trans and cis). The energy barrier to internal conversion from trans to cis is much higher than the thermal energy available in molecular clouds. Thus, only the most stable conformer (trans) is expected to exist in detectable amounts. We report the first interstellar detection of cis-HCOOH. Its presence in ultraviolet (UV) irradiated gas exclusively (the Orion Bar photodissociation region), with a low trans-to-cis abundance ratio of 2.8 ± 1.0, supports a photoswitching mechanism: a given conformer absorbs a stellar photon that radiatively excites the molecule to electronic states above the interconversion barrier. Subsequent fluorescent decay leaves the molecule in a different conformer form. This mechanism, which we specifically study with ab initio quantum calculations, was not considered in Space before but likely induces structural changes of a variety of interstellar molecules submitted to UV radiation.
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Affiliation(s)
- S Cuadrado
- Grupo de Astrofísica Molecular. Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Sor Juana Ines de la Cruz 3, E-28049 Cantoblanco, Madrid, Spain
| | - J R Goicoechea
- Grupo de Astrofísica Molecular. Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Sor Juana Ines de la Cruz 3, E-28049 Cantoblanco, Madrid, Spain
| | - O Roncero
- Instituto de Física Fundamental (IFF-CSIC). Calle Serrano 123, E-28006 Madrid, Spain
| | - A Aguado
- Facultad de Ciencias, Unidad Asociada de Química-Física Aplicada CSIC-UAM, Universidad Autónoma de Madrid, E-28049, Madrid, Spain
| | - B Tercero
- Grupo de Astrofísica Molecular. Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Sor Juana Ines de la Cruz 3, E-28049 Cantoblanco, Madrid, Spain
| | - J Cernicharo
- Grupo de Astrofísica Molecular. Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Sor Juana Ines de la Cruz 3, E-28049 Cantoblanco, Madrid, Spain
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Abstract
CONTEXT More than 30 cyanide derivatives of simple organic molecules have been detected in the interstellar medium, but only one dicarbonitrile has been found and that very recently. There is still a lack of high-resolution spectroscopic data particularly for dinitriles derivatives. The carbonyl cyanide molecule is a new and interesting candidate for astrophysical detection. It could be formed by the reaction of CO and CN radicals, or by substitution of the hydrogen atom by a cyano group in cyanoformaldehyde, HC(=O)CN, that has already been detected in the interstellar medium. AIMS The available data on the rotational spectrum of carbonyl cyanide is limited in terms of quantum number values and frequency range, and does not allow accurate extrapolation of the spectrum into the millimeter-wave range. To provide a firm basis for astrophysical detection of carbonyl cyanide we studied its millimeter-wave spectrum. METHODS The rotational spectrum of carbonyl cyanide was measured in the frequency range 152 - 308 GHz and analyzed using Watson's A- and S-reduction Hamiltonians. RESULTS The ground and first excited state of v5 vibrational mode were assigned and analyzed. More than 1100 distinct frequency lines of the ground state were fitted to produce an accurate set of rotational and centrifugal distortion constants up to the eighth order. The frequency predictions based on these constants should be accurate enough for astrophysical searches in the frequency range up to 500 GHz and for transition involving energy levels with J ≤ 100 and Ka ≤ 42. Based on the results we searched for interstellar carbonyl cyanide in available observational data without success. Thus, we derived upper limits to its column density in different sources.
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Affiliation(s)
- S B Bteich
- Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, Université de Lille 1, 59655 Villeneuve d'Ascq Cedex, France
| | - B Tercero
- Grupo de Astrofísica Molecular, Instituto de Ciencias de Materiales de Madrid (ICMM-CSIC). C/ Sor Juana Inés de la Cruz, 3, Cantoblanco, 28049 Madrid, Spain
| | - J Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Ciencias de Materiales de Madrid (ICMM-CSIC). C/ Sor Juana Inés de la Cruz, 3, Cantoblanco, 28049 Madrid, Spain
| | - R A Motiyenko
- Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, Université de Lille 1, 59655 Villeneuve d'Ascq Cedex, France
| | - L Margulès
- Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, Université de Lille 1, 59655 Villeneuve d'Ascq Cedex, France
| | - J-C Guillemin
- Institut des Sciences Chimiques de Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7, France
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Kolesniková L, Alonso JL, Bermúdez C, Alonso ER, Tercero B, Cernicharo J, Guillemin JC. The millimeter wave spectrum of methyl cyanate: a laboratory study and astronomical search in space<sup/>. Astron Astrophys 2016; 591:A75. [PMID: 27721514 PMCID: PMC5055117 DOI: 10.1051/0004-6361/201628140] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
AIMS The recent discovery of methyl isocyanate (CH3NCO) in Sgr B2(N) and Orion KL makes methyl cyanate (CH3OCN) a potential molecule in the interstellar medium. The aim of this work is to fulfill the first requirement for its unequivocal identification in space, i.e. the availability of transition frequencies with high accuracy. METHODS The room-temperature rotational spectrum of methyl cyanate was recorded in the millimeter wave domain from 130 to 350 GHz. All rotational transitions revealed A-E splitting owing to methyl internal rotation and were globally analyzed using the ERHAM program. RESULTS The data set for the ground torsional state of methyl cyanate exceeds 700 transitions within J″ = 10 - 35 and [Formula: see text] and newly derived spectroscopic constants reproduce the spectrum close to the experimental uncertainty. Spectral features of methyl cyanate were then searched for in Orion KL, Sgr B2(N), B1-b, and TMC-1 molecular clouds. Upper limits to the column density of methyl cyanate are provided.
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Affiliation(s)
- L Kolesniková
- Grupo de Espectroscopía Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain
| | - J L Alonso
- Grupo de Espectroscopía Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain
| | - C Bermúdez
- Grupo de Espectroscopía Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain
| | - E R Alonso
- Grupo de Espectroscopía Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain
| | - B Tercero
- Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Spain
| | - J Cernicharo
- Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Spain
| | - J-C Guillemin
- Institut des Sciences Chimiques de Rennes, École Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7, France
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Cernicharo J, Kisiel Z, Tercero B, Kolesniková L, Medvedev IR, López A, Fortman S, Winnewisser M, de Lucia FC, Alonso JL, Guillemin JC. A rigorous detection of interstellar CH 3NCO: An important missing species in astrochemical networks. Astron Astrophys 2016; 587:L4. [PMID: 27274565 PMCID: PMC4892348 DOI: 10.1051/0004-6361/201527531] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The recent analysis of the composition of the frozen surface of comet 67P/Churyumov-Gerasimenko has revealed a significant number of complex organic molecules. Methyl isocyanate (CH3NCO) is one of the more abundant species detected on the comet surface. In this work we report extensive characterization of its rotational spectrum resulting in a list of 1269 confidently assigned laboratory lines and its detection in space towards the Orion clouds where 399 lines of the molecule have been unambiguously identified. We find that the limited mm-wave laboratory data reported prior to our work require some revision. The abundance of CH3NCO in Orion is only a factor of ten below those of HNCO and CH3CN. Unlike the molecular abundances in the coma of comets, which correlate with those of warm molecular clouds, molecular abundances in the gas phase in Orion are only weakly correlated with those measured on the comet surface. We also compare our abundances with those derived recently for this molecule towards Sgr B2 (Halfen et al. 2015). A more accurate abundance of CH3NCO is provided for this cloud based on our extensive laboratory work.
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Affiliation(s)
- J Cernicharo
- Grupo de Astrofísica Molecular. Instituto de CC. de Materiales de Madrid (ICMM-CSIC). Sor Juana Inés de la Cruz 3, Cantoblanco, 28049 Madrid, Spain
| | - Z Kisiel
- Laboratory of Mm- and Submm- Spectroscopy. Institute of Physics, Polish Academy of Sciences. Al. Lotnikow 32/46, 02-668 Warszawa, Poland
| | - B Tercero
- Grupo de Astrofísica Molecular. Instituto de CC. de Materiales de Madrid (ICMM-CSIC). Sor Juana Inés de la Cruz 3, Cantoblanco, 28049 Madrid, Spain
| | - L Kolesniková
- Grupo de Espectroscopía Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopía y Bioespectroscopía, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain
| | - I R Medvedev
- Department of Physics, The Ohio State University, 191 W. Woodruff Ave, Columbus, OH 43210, USA; Wright State University, 3640 Colonel Glenn Hwy, Dayton, OH 45435, USA
| | - A López
- Grupo de Astrofísica Molecular. Instituto de CC. de Materiales de Madrid (ICMM-CSIC). Sor Juana Inés de la Cruz 3, Cantoblanco, 28049 Madrid, Spain
| | - S Fortman
- Department of Physics, The Ohio State University, 191 W. Woodruff Ave, Columbus, OH 43210, USA
| | - M Winnewisser
- Department of Physics, The Ohio State University, 191 W. Woodruff Ave, Columbus, OH 43210, USA
| | - F C de Lucia
- Department of Physics, The Ohio State University, 191 W. Woodruff Ave, Columbus, OH 43210, USA
| | - J L Alonso
- Grupo de Espectroscopía Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopía y Bioespectroscopía, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain
| | - J-C Guillemin
- Institut des Sciences Chimiques de Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7, France
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Tercero B, Cernicharo J, López A, Brouillet N, Kolesniková L, Motiyenko RA, Margulès L, Alonso JL, Guillemin JC. Searching for trans ethyl methyl ether in Orion KL . Astron Astrophys 2015; 582:L1. [PMID: 26869726 PMCID: PMC4747151 DOI: 10.1051/0004-6361/201526255] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report on the tentative detection of trans ethyl methyl ether (tEME), t-CH3CH2OCH3, through the identification of a large number of rotational lines from each one of the spin states of the molecule towards Orion KL. We also search for gauche-trans-n-propanol, Gt-n-CH3CH2CH2OH, an isomer of tEME in the same source. We have identified lines of both species in the IRAM 30 m line survey and in the ALMA Science Verification data. We have obtained ALMA maps to establish the spatial distribution of these species. Whereas tEME mainly arises from the compact ridge component of Orion, Gt-n-propanol appears at the emission peak of ethanol (south hot core). The derived column densities of these species at the location of their emission peaks are ≤(4.0 ± 0.8) × 1015 cm-2 and ≤(1.0 ± 0.2)× 1015 cm-2 for tEME and Gt-n-propanol, respectively. The rotational temperature is ~100 K for both molecules. We also provide maps of CH3OCOH, CH3CH2OCOH, CH3OCH3, CH3OH, and CH3CH2OH to compare the distribution of these organic saturated O-bearing species containing methyl and ethyl groups in this region. Abundance ratios of related species and upper limits to the abundances of non-detected ethers are provided. We derive an abundance ratio N(CH3OCH3)/N(tEME) ≥ 150 in the compact ridge of Orion.
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Affiliation(s)
- B Tercero
- Grupo de Astrofísica Molecular. Instituto de CC. de Materiales de Madrid (ICMM-CSIC). Sor Juana Inés de la Cruz, 3, Cantoblanco, 28049 Madrid, Spain
| | - J Cernicharo
- Grupo de Astrofísica Molecular. Instituto de CC. de Materiales de Madrid (ICMM-CSIC). Sor Juana Inés de la Cruz, 3, Cantoblanco, 28049 Madrid, Spain
| | - A López
- Grupo de Astrofísica Molecular. Instituto de CC. de Materiales de Madrid (ICMM-CSIC). Sor Juana Inés de la Cruz, 3, Cantoblanco, 28049 Madrid, Spain ; Dpto. de Astrofísica, CAB, INTA-CSIC, Crta Torrejón-Ajalvir, km 4, 28850 Torrejón de Ardoz, Madrid, Spain
| | - N Brouillet
- Université Bordeaux, LAB, UMR 5804, 33270 Floirac, France ; CNRS, LAB, UMR 5804, 33270 Floirac, France
| | - L Kolesniková
- Grupo de Espectroscopía Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopía y Bioespectroscopía, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain
| | - R A Motiyenko
- Laboratoire de Physique des Lasers, Atomes, et Molécules, UMR CNRS 8523, Université de Lille I, 59655 Villeneuve d'Ascq Cédex, France
| | - L Margulès
- Laboratoire de Physique des Lasers, Atomes, et Molécules, UMR CNRS 8523, Université de Lille I, 59655 Villeneuve d'Ascq Cédex, France
| | - J L Alonso
- Grupo de Espectroscopía Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopía y Bioespectroscopía, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, 47011 Valladolid, Spain
| | - J-C Guillemin
- Institut des Sciences Chimiques de Rennes, École Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7, France
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Cernicharo J, Bailleux S, Alekseev E, Fuente A, Roueff E, Gerin M, Tercero B, Treviño-Morales SP, Marcelino N, Bachiller R, Lefloch B. TENTATIVE DETECTION OF THE NITROSYLIUM ION IN SPACE. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/0004-637x/795/1/40] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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