SIMBAD references

Highly collimated multiple bipolar flows are detected with a 3'' resolution in the HCO⁺ (J = 3-2) and HCN (J = 3-2) lines in the young planetary nebula NGC 7027 with the Submillimeter Array. The HCO⁺ and HCN flows coincide in location and velocity with compact and fast CO flows detected with ∼6'' resolutions with other millimeter arrays. The equatorial molecular torus of NGC 7027 is captured in HCO⁺ emission in the present observations. The HCO⁺ emission also closely follows the H₂emission, indicating that the present observations probe the photon-dominated region of the molecular envelope of NGC 7027.