Discovery of two metallic cyanoacetylides in IRC+10216: HMgCCCN and NaCCCN

Authors :: Cabezas, C.
Pardo, J. R.
Agundez, M.
Tercero, B.
Marcelino, N.
Endo, Y.
de Vicente, P.
Guelin, M.
Cernicharo, J.
Source :: A&A 672, L12 (2023)
Publication Year :: 2023
Abstract: We report on the detection of a series of six lines in the ultra-deep Q-band integration toward IRC+10216 carried out with the Yebes 40m telescope, which are in harmonic relation with integer quantum numbers J from 12 to 18. After a detailed analysis of all possible carriers, guided by high-level quantum chemical calculations, we conclude that the lines belong to HMgCCCN, named hydromagnesium cyanoacetylide. The rotational temperature and column density derived for HMgCCCN are 17.1 +/- 2.8K and (3.0 +/- 0.6) e12 cm-2, respectively. The observed abundance ratio between MgCCCN and HMgCCCN is 3. In addition, we report the discovery in space, also toward IRC+10216, of sodium cyanoacetylide, NaCCCN, for which accurate laboratory data are available. For this species we derive a rotational temperature of 13.5 +/- 1.7K and a column density of (1.2 +/- 0.2) e11 cm-2.<br />Comment: Accepted in Astronomy & Astrophysics as Letter to the Editor on April 3rd, 2023