Discovery of Interstellar 2-Cyanoindene (2-C₉H₇CN) in GOTHAM Observations of TMC-1

The Astrophysical Journal Letters, Journal Year: 2022, Volume and Issue: 938(2), P. L12 - L12

Published: Oct. 1, 2022

We present laboratory rotational spectroscopy of five isomers cyanoindene (2-, 4-, 5-, 6-, and 7-cyanoindene) using a cavity Fourier-transform microwave spectrometer operating between 6-40 GHz. Based on these measurements, we report the detection 2-cyanoindene (1H-indene-2-carbonitrile; 2-C$_9$H$_7$CN) in GOTHAM line survey observations dark molecular cloud TMC-1 Green Bank Telescope at centimeter wavelengths. Using combination Markov Chain Monte Carlo (MCMC), spectral stacking, matched filtering techniques, find evidence for presence this molecule 6.3$\sigma$ level. This provides first direct observation ratio cyano-substituted polycyclic aromatic hydrocarbon (PAH) to its pure counterpart, case indene, same source. discuss possible formation chemistry species, including why have only detected one TMC-1. then examine overall hydrocarbon:CN-substituted across other simpler as well compare those ratios predicted by astrochemical models. conclude that while models are not yet sufficiently accurate reproduce absolute abundances they do good job predicting further solidifying -CN tagged species excellent proxies their fully-symmetric counterparts.

Language: Английский

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The UMIST Database for Astrochemistry 2022

Astronomy and Astrophysics, Journal Year: 2023, Volume and Issue: 682, P. A109 - A109

Published: Nov. 6, 2023

Context . Detailed astrochemical models are a key component to interpret the observations of interstellar and circumstellar molecules since they allow important physical properties gas its evolutionary history be deduced. Aims We update one most widely used databases reflect advances in experimental theoretical estimates rate coefficients respond large increase number detected space our last release 2013. Methods present sixth UMIST Database for Astrochemistry (UDfA), major expansion gas-phase chemistry that describes synthesis molecules. Since release, we have undertaken review literature which has increased reactions by over 40% total 8767 species 55% 737. made particular attempt include many new past decade, including those from QUIJOTE GOTHAM surveys, as well providing references original data sources. Results use database investigate chemistries appropriate both O-rich C-rich conditions TMC-1 envelope AGB star IRC+10216 identify successes failures only models. Conclusions This is significant improvement UDfA database. For dark cloud models, calculations match around 60% abundances observed within an order magnitude. There species, however, not included model either because their unknown or likely formed via surface on icy grains. Future laboratory work needed such reaction networks.

Language: Английский

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OS DIFERENTES MARCOS DA BIOTECNOLOGIA INDUSTRIAL NO BRASIL E NO MUNDO

Revista SODEBRAS, Journal Year: 2023, Volume and Issue: 18(206), P. 08 - 23

Published: Feb. 1, 2023

object of study and organizational strategy.

Language: Английский

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Identification and characterization of a new ensemble of cometary organic molecules

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: June 25, 2022

Abstract In-situ study of comet 1P/Halley during its 1986 apparition revealed a surprising abundance organic coma species. It remained unclear, whether or not these species originated from polymeric matter. Now, high-resolution mass-spectrometric data collected at 67P/Churyumov-Gerasimenko by ESA’s Rosetta mission unveil the chemical structure complex cometary organics. Here, we identify an ensemble individual molecules with masses up to 140 Da while demonstrating inconsistency relevant amounts The has average composition C 1 H 1.56 O 0.134 N 0.046 S 0.017 , identical meteoritic soluble matter, and includes plethora chain-based, cyclic, aromatic hydrocarbons approximate ratio 6:3:1. Its compositional structural properties, except for H/C ratio, resemble those other Solar System reservoirs organics—from material in Saturnian ring rain insoluble matter –, which is compatible shared prestellar history.

Language: Английский

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Fingerprinting fragments of fragile interstellar molecules: dissociation chemistry of pyridine and benzonitrile revealed by infrared spectroscopy and theory

Faraday Discussions, Journal Year: 2023, Volume and Issue: 245, P. 221 - 244

Published: Jan. 1, 2023

Fragmentation pathways of benzonitrile and pyridine are elucidated using cryogenic infrared ion spectroscopy, quantum-chemical calculations molecular dynamics simulations.

Language: Английский

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Detection of Interstellar E-1-cyano-1,3-butadiene in GOTHAM Observations of TMC-1

The Astrophysical Journal, Journal Year: 2023, Volume and Issue: 948(2), P. 133 - 133

Published: May 1, 2023

Abstract We report the detection of lowest-energy conformer E -1-cyano-1,3-butadiene ( -1- C 4 mathvariant="normal">H 5 CN ), a linear isomer pyridine, using fourth data reduction GBT Observations TMC-1: Hunting for Aromatic Molecules (GOTHAM) deep spectral survey toward TMC-1 with 100 m Green Bank Telescope. perform velocity stacking and matched-filter analyses Markov chain Monte Carlo simulations find evidence presence this molecule at 5.1 σ level. derive total column density ${3.8}_{-0.9}^{+1.0}\times {10}^{10}$?> 3.8 − 0.9 + 1.0 × 10 cm −2 , which is predominantly found two four components we observe TMC-1. use as proxy constraining gas-phase abundance apolar hydrocarbon 1,3-butadiene. Based on three-phase astrochemical modeling code NAUTILUS an expanded chemical network, our model underestimates cyano-1,3-butadiene by factor 19, peak 2.34 × 10 Compared to results obtained in previous GOTHAM analyses, 1,3-butadiene increased about orders magnitude. Despite increase, modeled abundances aromatic species do not appear change remain underestimated one Meanwhile, five-membered ring molecules increase proportionally discuss implications bottom-up formation routes polycyclic molecules.

Language: Английский

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Theoretical study of aromatic and N-heterocycles: Potential carriers of interstellar aromatic infrared bands

Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy, Journal Year: 2025, Volume and Issue: 332, P. 125811 - 125811

Published: Feb. 1, 2025

Language: Английский

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Photoabsorption and Photoionization Cross-Sections and Asymmetry Parameters of Pyrrole in the Vacuum-Ultraviolet Energy Range

ACS Physical Chemistry Au, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 24, 2025

Language: Английский

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VUV Photoionization Induced Proton Transfer and Formation of New Covalent Bonds in Pyridine–Methanol Complex

The Journal of Physical Chemistry A, Journal Year: 2025, Volume and Issue: unknown

Published: March 20, 2025

Ion–molecule reactions are a crucial form of reaction in space that can reveal the formation mechanisms and evolutionary processes some complex interstellar molecules even prebiotic molecules. In this study, infrared spectra pyridine (Pyd) methanol (CH3OH) or deuterated (CH3OD) clusters were measured spectral range 2400–3800 cm–1 using an infrared-vacuum ultraviolet (IR-VUV) scheme. The geometric conformer, possible products, paths investigated utilizing quantum chemical calculations. By comparing experimental theoretically calculated spectra, we found only unique hydrogen-bonded structure exists within Pyd-CH3OH complex, characterized by linear hydrogen bond conformer between two constituent On other hand, interestingly, observed relatively weak NH vibrational peak at 3383 both cationic Pyd-CH3OD, suggesting proton transfer has occurred via least distinct pathways. These pathways likely involve from either OH group CH3 CH3OH to nitrogen atom Pyd, with being predominant route. Through theoretical calculations, also new C–C be formed moieties after reactions.

Language: Английский

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The AstroPAH 10 Years of Science Review

Space Science Reviews, Journal Year: 2025, Volume and Issue: 221(4)

Published: May 6, 2025

Language: Английский

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