On C5H3N Isomers in the Interstellar Medium

K. L. K. Lee, R. A. Loomis, A. M. Burkhardt, I. R. Cooke, C. Xue, M. A. Siebert, C. N. Shingledecker, A. Remijan, S. B. Charnley, M. C. McCarthy, and B. A. McGuire
reported on the
Discovery of Interstellar //trans//-Cyanovinylacetylene (HC≡CCH=CHC≡N) and Vinylcyanoacetylene (H<sub>2</sub>C=CHC<sub>3</sub>N) in GOTHAM Observations of TMC-1
Astrophys. J. Lett. 908, Art. No. L11 (2021).
The observations were obtained in the course of the line survey Green Bank Telescope Observations of TMC-1: Hunting for Aromatic Molecules. The data were recorded with very high resolution which resolves, at least in part, the complex velocity structure and the 14N hyperfine structure splitting. 2E-Penten-4-ynenitrile (here called trans-E-cyanovinylacetylene) and cyanoethynylethene (aka 4-penten-2-ynenitrile, here called vinylcyanoacetylene) were indentified through line-stacking with decent signal-to-noise ratios and very similar abundances. The significance of the cyanoethynylethene detections is somewhat on the edge (5.5σ). Two other isomers, 2Z-Penten-4-ynenitrile (here called trans-Z-cyanovinylacetylene) and 2-methylene-3-butynenitrile (here called cis-cyanovinylacetylene), were not identified.


Contributor(s): H. S. P. Müller; 02, 2021