Discovery of CH2CCHC4H and a rigorous detection of CH2CCHC3N in TMC-1 with the QUIJOTE line survey

Abstract

Using the QUIJOTE line survey in the 32.0-50.4 GHz range, we report the discovery of the molecule CH2CCHC4H towards the prestellar cold core TMC-1 in the Taurus region. We also present a rigorous detection of CH2CCHC3N, along with its detailed analysis. We identified a total of twenty rotational transitions for each one of these molecules. The rotational quantum numbers range from Ju=17 up to 24 and Ka<=3. The column density for CH2CCHC4H is N=(2.2+/-0.2)x 1E12 cm-2, while for CH2CCHC3N, we derived N=(1.2+/-0.15) x 1E11 cm-2. The rotational temperature is 9.0+/-0.5 K for both species. The abundance ratio between CH2CCHC4H and CH2CCHC3N is 18+/-4. We also compared the column densities of these species with those of their isomers CH3C6H and CH3C5N, derived from their J=20-19 up to J=30-29 rotational transitions observed with the QUIJOTE line survey. The observed abundances for all these species are reasonably well explained by state-of-the-art chemical models of TMC-1. The observed astronomical frequencies were merged with laboratory frequencies from the literature to derive improved spectroscopic parameters.

Astronomy and Astrophysics, in press. arXiv admin note: text overlap with arXiv:2112.01130

References in corpus (12)

• Detection of Two Interstellar Polycyclic Aromatic Hydrocarbons via Spectral Matched Filtering
• Pure hydrocarbon cycles in TMC-1: Discovery of ethynyl cyclopropenylidene, cyclopentadiene and indene
• Discovery of benzyne, o-C6H4, in TMC-1 with the QUIJOTE line survey
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• The interstellar chemistry of C3H and C3H2 isomers
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• Discovery of CH2CHCCH and detection of HCCN, HC4N, CH3CH2CN, and, tentatively, CH3CH2CCH in TMC-1
• Interstellar Detection of 2-Cyanocyclopentadiene, C${}_5$H${}_5$CN, a Second Five-Membered Ring Toward TMC-1
• A study of C4H3N isomers in TMC-1: line by line detection of HCCCH2CN
• Cumulene carbenes in TMC-1: Astronomical discovery of $l$-H${}_2$C${}_5$
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Cited by in corpus (7)

• Discovery of fulvenallene in TMC-1 with the QUIJOTE line survey
• Discovery of two cyano derivatives of acenaphthylene (C${}_{12}$H${}_8$) in TMC-1 with the QUIJOTE line survey
• Carbon-Chain Chemistry in the Interstellar Medium
• Discovery of two new interstellar molecules with QUIJOTE: HCCCHCCC and HCCCCS
• Laboratory and astronomical discovery of cyanothioketene, NCCHCS, in the cold starless core TMC-1
• Discovery of CH3CHCO in TMC-1 with the QUIJOTE line survey
• Chemistry of Dark Molecular Clouds