We report the first laboratory and interstellar detection of the α-cyanovinyl radical (H2CCCN). This species was produced in the laboratory by a gas discharge of a mixture of vinyl cyanide, CHCHCN and Ne, and its rotational spectrum was analyzed using a Balle-Flygare narrowband Fourier transform microwave spectrometer operating in the frequency region8. Characterized. -40GHz.
The observed spectrum shows a complex structure due to tunnel splitting between two torsional sublevels (0+ and 0-) of the ground vibrational state, resulting from large-amplitude reversal motion. Furthermore, it is necessary to distinguish between ortho-H2CCCN and para-H2CCCN due to the presence of two equivalent hydrogen nuclei. A least-squares analysis reproduces the observed transition frequencies with approximately 100 standard deviations. 3 kHz. Using laboratory predictions, this radical is detected within the cold dark cloud TMC-1 using the Yeves 40-m telescope and the QUIJOTE line survey.
Rotational transitions of 404-303 and 505-404, composed of several hyperfine components, were observed in the range of 31.0-50.4 GHz. Employing a rotation temperature of 6K, column densities of (1.4+/-0.2)e11 cm-2 and (1.1+/-0.2)e11 cm-2 are obtained for ortho-H2CCCN and para-H2CCCN, respectively. The C + CH3CN reaction, and possibly also the N + CH2CCH reaction, emerge as the most likely routes to his H2CCCN in TMC-1.
C. Cabezas, J. Tan, M. Agundez, K. Seiki, Yuya Sumiyoshi, Yuya Oshima, B. Tercero, N. Marcelino, R. Fuentetaya, P. De Vicente, Y. Endo, J. Cernicaro
Comment: Accepted for publication in A&A Letters on July 18, 2023
Subject: Galactic Astrophysics (astro-ph.GA)
Quote: arXiv:2307.09127 [astro-ph.GA] (or arXiv:2307.09127v1 [astro-ph.GA] for this version)
Birthplace: Carlos Cabezas
[v1] Tuesday, July 18, 2023 10:17:47 UTC (626 KB)