Isocyanobutadiyne, HC4NC, in the Interstellar Medium

C. Xue, E. Willis, R. Loomis, K. Lee, A. Burkhardt, C. Shingledecker, S. Charnley, M. Cordiner, S. Kalenskii, M. McCarthy, E. Herbst, A. Remijan, and B. McGuire
reported on the
Detection of Interstellar HC<sub>4</sub>NC and an Investigation of Isocyanopolyyne Chemistry under TMC-1 Conditions
Astrophys. J. Lett. 900, Art. No. L9 (2020).
The observations were obtained in the course of the line survey GOTHAM (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 of the J = 8 → 7, 9 → 9, and 10 → 9 transitions near 22.4, 25.2, and 28.0 GHz, respectively, at the expense of noise levels of about the same level as the individual lines. The analysis was improved by employing a stacking technique. The HC4NC to HC4CN ratio is about 1 to 200, while the HC2NC to HC2CN ratio is about 1 to 50.

Almost at the same time,
J. Cernicharo, N. Marcelino, M. Agúndez, C. Bermúdez, C. Cabezas, B. Tercero, and J. R. Pardo
reported on the
Discovery of HC<sub>4</sub>NC in TMC-1: A study of the isomers of HC<sub>3</sub>N, HC<sub>5</sub>N, and HC<sub>7</sub>N
Astron. Astrophys. 642, Art. No. L8 (2020).
The observations were obtained with the Yebes 40m radio telescope in the course of a line survey covering 31.0–50.3 GHz and cover J“ = 11 to 15 of the molecule. The findings are compatible with the ones mentioned above.


Contributor(s): H. S. P. Müller; 10, 2020