J. Cernicharo, J. R. Pardo, C. Cabezas, M. Agúndez, B. Tercero, N. Marcelino, R. Fuentetaja, M. Guélin, and P. de Vicente
reported on the
Discovery of the C₇N⁻ Anion in TMC-1 and IRC +10216
Astron. Astrophys. 670, (2023), Art. No. L19.
Six transitions with 26 ≤ J“ ≤ 31 and 17 transitions with 26 ≤ J” ≤ 42 were detected toward the dark cloud TMC-1 and the C-rich late-type star CW Leonis, respectively, in the course of two molecular line surveys. The identification relies on quantum-chemical observations as no laboraotory data exist to date, as in the case of C₅N⁻. The rotational temperature T_rot was fit as 6.0 ± 0.5 K in TMC-1 and as 26.6 ± 1.8 K toward CW Leonis; both values are similar to those of C₅N⁻. The C₅N⁻ to C₇N⁻ in TMC-1 is ~5, toward CW Leonis ~2.4.

Contributor(s): H. S. P. Müller; 02, 2023