SIMBAD references

We report the first identification in space of H₂NC, a high-energy isomer of H₂CN that has been largely ignored in chemical and astrochemical studies. The observation of various unidentified lines around 72.2 GHz in the cold dark cloud L483 motivated the search and successful detection of additional groups of lines in harmonic relation. Following an exhaustive high-level ab initio screening of possible carriers, we confidently assign the unidentified lines to H₂NC based on the good agreement between the astronomical and theoretical spectroscopic parameters alongside sound spectroscopic and astrochemical arguments. The observed frequencies are used to precisely characterize the rotational spectrum of H₂NC. This species is also detected in the cold dark cloud B1-b and the z = 0.89 galaxy in front of the quasar PKS 1830-211. We derive H₂NC/H₂CN abundance ratios ∼1 in L483 and B1-b and 0.27 toward PKS 1830-211. Neither H₂NC nor H₂CN are detected in the dark cloud TMC-1, which seriously undermines the previous identification of H₂CN in this source. We suggest that the H₂NC/H₂CN ratio behaves as the HNC/HCN ratio, with values close to one in cold dense clouds and below one in diffuse clouds. The reactions N + CH₃ and C + NH₃ emerge as strong candidates for the production of H₂NC in interstellar clouds. Further studies on these two reactions are needed to evaluate the yield of H₂NC. Due to the small number of atoms involved, it should be feasible to constrain the chemistry behind H₂NC and H₂CN, just as has been done for HNC and HCN, as this could allow for the H₂NC/H₂CN ratio to be applied as a probe of chemical or physical conditions of the host clouds.