===== On Ethynylcyclopropenylidene in the ISM =====

J. Cernicharo, M. Agúndez, C. Cabezas, B. Tercero, N. Marcelino, J. R. Pardo, and P. de Vicente\\
reported on\\
**[[https://doi.org/10.1051/0004-6361/202141156|Pure hydrocarbon cycles in TMC-1: Discovery of ethynylcyclopropenylidene, cyclopentadiene, and indene]]**\\
//Astron. Astrophys.// **649**, Art. No. L15 (2021).\\
Ethynylcyclopropenylidene, //c//-C<sub>3</sub>HCCH, was identified through 12 unblended or slightly blended mostly //b//-type transitions with 1 ≤ //J// ≤ 10 and //K<sub>a</sub>// ≤ 1 in the course of a molecular line survey of the prototypical cold dark molecular cloud TMC-1 carried out with the Yebes 40 m radio telescope between 32.8 and 49.2 GHz. A value of //T//<sub>rot</sub> = 8 ± 3 K was derived through a rotation diagram, but the model is more compatible with 10 K. The column density of //c//-C<sub>3</sub>HCCH is about a factor of 190 lower than that of //c//-C<sub>3</sub>H<sub>2</sub> and about a factor of 20 lower than that of //c//-C<sub>3</sub>H.\\



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Contributor(s): H. S. P. Müller; 05, 2021

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