Detection and Chemical Modeling of Complex Prebiotic Molecule Cyanamide in the Hot Molecular Core G31.41 + 0.31

In the interstellar medium (ISM), the complex prebiotic molecule cyanamide (NH2CN) plays a key role in producing adenine (C5H5N5), purines (C5H4N4), pyrimidines (C4H4N2), and other biomolecules via a series of reactions. Therefore, studying the emission lines of NH2CN is important for understanding the hypothesis of the presolar origin of life in the universe. We present the detection of the rotational emission lines of NH2CN with vibrational states v = 0 and 1 toward the hot molecular core G31.41 + 0.31 using the high-resolution 12 meter array of the Atacama Large Millimeter/Submillimeter Array (ALMA) band 3. The estimated column density of NH2CN toward G31.41 + 0.31 using the local thermodynamic equilibrium (LTE) model is (7.21 ± 0.25) × 1015 cm–2 with an excitation temperature of 250 ± 25 K. The abundance of NH2CN with respect to H2 toward G31.41 + 0.31 is (7.21 ± 1.46) × 10–10. The NH2CN and NH2CHO column density ratio toward G31.41 + 0.31 is 0.13 ± 0.02. We compare the estimated abundance of NH2CN with that of other hot cores and corinos and observe that the abundance of NH2CN toward G31.41 + 0.31 is nearly similar to that of the hot molecular core G358.93 – 0.03 MM1, the hot corinos IRAS 16293-2422 B, and NGC 1333 IRAS4A2. We compute the two-phase warm-up chemical model of NH2CN using the gas-grain chemical code UCLCHEM, and after chemical modeling, we notice that the observed and modeled abundances are nearly similar. After chemical modeling, we conclude that the neutral–neutral reaction between NH2 and CN is responsible for the production of NH2CN on the grain surface of G31.41 + 0.31.