Astrochemistry

Discovery Of Interstellar 1-cyanopyrene: A Four-ring Polycyclic Aromatic Hydrocarbon In TMC-1

By Keith Cowing
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astro-ph.GA
October 5, 2024
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Discovery Of Interstellar 1-cyanopyrene: A Four-ring Polycyclic Aromatic Hydrocarbon In TMC-1
GOTHAM spectra showcasing several 1-cyanopyrene lines detected in TMC-1 observations. The original GOTHAM observational data for which one channel corresponds to 1.4 kHz were smoothed with a Hanning window to a resolution of 14 kHz, depicted in black. The spectrum of 1-cyanopyrene is overplotted in violet using source-dependent molecular parameters as reported in Table S4. The quantum numbers of each transition, ignoring 14N nuclear electric quadrupole splitting, are reported. Each line contains multiple closely spaced K-components of each transition which are denoted α, β, γ, δ = {0,1}, {1,2}, {2,3}, {3,4}. — astro-ph.GA

Polycyclic aromatic hydrocarbons (PAHs) are thought to be the most abundant class of molecules in space, yet their interstellar lifecycle is poorly understood due to difficulties detecting individual PAHs.

Here, we present the discovery of 1-cyanopyrene, a 4-ring PAH, in the dense cloud TMC-1 using the 100-m Green Bank Telescope. We derive an abundance of ~1.52 x 1012 cm−2, estimating that pyrene accounts for up to 0.03-0.3% of the carbon in TMC-1 and up to 1% within comets. Our findings agree with analysis of pyrene from asteroid Ryugu, which suggests a cold, interstellar origin.

The abundance indicates pyrene is an “island of stability” in interstellar PAH chemistry, and suggests that the carbon supplied to planetary systems, carried by PAHs, originates in cold clouds.

Gabi Wenzel, Ilsa R. Cooke, P. Bryan Changala, Edwin A. Bergin, Shuo Zhang, Andrew M. Burkhardt, Alex N. Byrne, Steven B. Charnley, Martin A. Cordiner, Miya Duffy, Zachary T. P. Fried, Harshal Gupta, Martin S. Holdren, Andrew Lipnicky, Ryan A. Loomis, Hannah Toru Shay, Christopher N. Shingledecker, Mark A. Siebert, D. Archie Stewart, Reace H. J. Willis, Ci Xue, Anthony J. Remijan, Alison E. Wendlandt, Michael C. McCarthy, Brett A. McGuire

Comments: Version of manuscript revised to comply with licensing requirements
Subjects: Astrophysics of Galaxies (astro-ph.GA)
Cite as: arXiv:2410.00657 [astro-ph.GA] (or arXiv:2410.00657v2 [astro-ph.GA] for this version)
https://doi.org/10.48550/arXiv.2410.00657
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Submission history
From: Brett McGuire
[v1] Tue, 1 Oct 2024 13:14:06 UTC (4,553 KB)
[v2] Fri, 4
Oct 2024 16:42:13 UTC (3,970 KB)
https://arxiv.org/abs/2410.00657

Astrobiology, Astrochemistry,

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻