Spectral-line survey of IRC+10216 at 293-355GHz

A total of 442 lines were detected, more than 200 for the first time; 149 are unassigned. Maps at an angular resolution of ~3" were obtained for each line.

A substantial new population of narrow lines with an expansion velocity of ~4km/s (i.e., ~30% of the terminal velocity) was detected. Most of these are attributed to rotational transitions within vibrationally excited states, emitted from energy levels above the {nu}=0, J=0 ground state with excitation energy of 1000-3000K. Emission from these lines appears to be centered on the star with an angular extent of <1".