C. Cabezas, M. Agúndez, N. Marcelino, B. Tercero, J. R. Pardo, P. de Vicente, and J. Cernicharo
reported on the
Discovery of Interstellar 3-Cyanopropargyl Radical, CH<sub>2</sub>CCCN
Astron. Astrophys. 654, Art. No. L9 (2021).
ortho-CH2C3N was identified through three a-type transitions with J = 8 − 7 to 10 − 9 and Ka = 0 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 31.0 and 50.4 GHz. These transitions displayed partially resolved fine and hyperfine structure splitting; few components were blended by lines of other species. Also observed were four transitions of para-CH2C3N with J = 8 − 7 or 9 − 8 and Ka = 1, which displayed well resolved fine structure splitting; some of these lines were also blended. A value of Trot = 7 ± 1 K was derived. The column density of CH2C3N is about a factor of 100 lower than that of CH2CN. And while CH2C3N is roughly a factor of 10 less abundant than CH3C3N, CH2CN is more abundant than CH3CN by a factor of about 3.
Contributor(s): H. S. P. Müller; 11, 2021