Show pageOld revisionsBacklinksBack to top This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong. ===== Detection of Ethynyloxomethylium, HC3O+, in the ISM ===== J. Cernicharo, N. Marcelino, M. Agúndez, Y. Endo, C. Cabezas, C. Bermúdez, B. Tercero, and P. de Vicente\\ reported on the\\ **[[https://doi.org/10.1051/0004-6361/202039351|Discovery of HC<sub>3</sub>O<sup>+</sup> in Space: The Chemistry of O-bearing Species in TMC-1]]**\\ //Astron Astrophys.// **642**, Art. No. L17 (2020).\\ Two transitions, //J"// = 3 and 4 near 35.7 and 44.6 GHz, of a new, unknown molecule were detected 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. Subsequently, two additional transitions, //J"// = 9 and 10 near 89.2 and 98.1 GHz, were identified in data from an older IRAM 30 m line survey of TMC-1. Laboratory measurements confirmed the identity of the molecule as ethynyloxomethylium.\\ The abundance ratio of C<sub>3</sub>O to HC<sub>3</sub>O<sup>+</sup> is ~7, extremely low, whereas astrochemical modeling with protonation of C<sub>3</sub>O as dominant source of HC<sub>3</sub>O<sup>+</sup> yielded a ratio of ~500 at steady state. The abundance ratio of C<sub>3</sub>S to HC<sub>3</sub>S<sup>+</sup> should be even lower because of the larger proton affinity of C<sub>3</sub>S compared to C<sub>3</sub>O. However, HC<sub>3</sub>S<sup>+</sup> was not detected, and the C<sub>3</sub>S to HC<sub>3</sub>S<sup>+</sup> ratio was evaluated to be larger than 25, strongly suggesting that protonation of C<sub>3</sub>O is not an important source of HC<sub>3</sub>O<sup>+</sup> in TMC-1.\\ ---- Contributor(s): H. S. P. Müller 10, 2020 ---- molecules/ism/hc3o.txt Last modified: 2020/10/29 09:40by mueller