2024PASJ...76...54L

The peptide-like molecule cyanoformamide (NCCONH₂) is the cyano (CN) derivative of formamide (NH₂CHO). It is known to play a role in the synthesis of nucleic acid precursors under prebiotic conditions. In this paper, we present a tentative detection of NCCONH₂ in the interstellar medium with the Atacama Large Millimeter/submillimeter Array (ALMA) archive data. 10 unblended lines of NCCONH₂ were seen around 3σ noise levels toward Sagittarius B2(N1E), a position that is slightly offset from the continuum peak. The column density of NCCONH₂ was estimated to be 2.4 × 10¹⁵ cm^–2, and the fractional abundance of NCCONH₂ toward Sgr B2(N1E) was 6.9 × 10^–10. The abundance ratio between NCCONH₂ and NH₂CHO is estimated to be ∼0.01. We also searched for other peptide-like molecules toward Sgr B2(N1E). The abundances of NH₂CHO, CH₃NCO and CH₃NHCHO toward Sgr B2(N1E) were about 1/10 of those toward Sgr B2(N1S), while the abundance of CH₃CONH₂ was only 1/20 of that toward Sgr B2(N1S).