SIMBAD references

Submillimeter lines of H₂O and NH₃have been detected in the carbon star IRC +10216 (CW Leo) with the Odin submillimeter satellite. The detection of the J_K-^,K+^₌₁10_⟶101_557 GHz line of ortho-H₂O confirms the earlier detection in the same source with SWAS. The detection of the J_K=1₀⟶0₀572 GHz line represents the first observation of the ground-state rotational transition of NH₃in a stellar envelope. By fitting a molecular line transfer model to the observed lines, we derive an ortho-H₂O abundance of 2.4x10^–6, which is consistent with estimates from the SWAS observation. The derived ortho-NH₃abundance of 1x10^–6 relative to H₂is significantly higher than those derived from 24 GHz inversion transitions and is slightly higher than those from vibrational transitions in the infrared band. The high H₂O and NH₃abundances in the carbon-rich star IRC +10216 underscore shortcomings in the conventional gas-phase LTE and non-LTE chemical models.