Reports on Cyanamide, H2NCN, in the ISM

Cyanamide seems to be a fairly typical hot core molecule that is quite abundant. The 41,3 – 31,2 and 51,4 – 41,3 transitions of this molecule near 80.5 and 100.6 GHz were detected with the NRAO 11 m telescope toward Sgr B2 by
B. E. Turner, H. S. Liszt, N. Kaifu, and A. G. Kisliakov,
Microwave Detection of Interstellar Cyanamide
Astrophys. J. 201, L149–L152 (1975).
Additional transitions were detected later. Furthermore, the molecule has also been detected in other hot core sources.

A. Coutens, E. R. Willis, R. T. Garrod, H. S. P. Müller, T. L. Bourke, H. Calcutt, M. N. Drozdovskaya, J. K. Jørgensen, N. F. W. Ligterink, M. V. Persson, G. Stéphan, M. H. D. van der Wiel, E. F. van Dishoeck, and S. F. Wampfler
reported the
First Detection of Cyanamide (NH2CN) towards Solar-type Protostars
Astron. Astrophys. 612, Art. No. A107 (2018).
The Protostellar Interferometric Line Survey (PILS) of IRAS 16293–2422 with ALMA was used to identify 11 transitions of both tunneling components of cyanamide toward source B. A quantitative analysis was complicated by the interplay between absorption from the less dense envelope and emission from the hot corino associated with the secondary protostar. The situation is more favorable for the NH213CN and NHDCN isotopologs for which 3 and 9 lines, respectively, were detected. The column density of NH2CN in the hot corino was derived assuming a 12C/13C ratio of 68, typical for the local ISM. This yielded a D/H ratio per H atom of about 1.7 %, similar to what was observed for formamide from the same survey. Please note that a lower 12C/13C ratio would yield an equivalently higher D/H ratio.

The authors also detected NH2CN toward NGC 1333 IRAS2A with PdBI. Three lines come from their own observations, and five more apparently unblended lines from a study in which these lines remained unidentified. Cyanamide appears to be usually less abundant than formamide by factors of a few, but may be similarly abundant in Orion KL.


Contributor(s): H. S. P. Müller; 12, 2011; 05, 2018