SIMBAD references

We describe a detailed depth- and time-dependent model of the molecular cloud associated with the ultracompact HII region G 34.3+0.15. Previous work on observations of NH₃ and CS indicates that the molecular cloud has three distinct physical components:- an ultracompact hot core, a compact hot core and an extended halo. We have used the physical parameters derived from these observations as input to our detailed chemical kinetic modelling. The results of the model calculations are discussed with reference to the different chemistries occuring in each component and are compared with abundances derived from our recent spectral line survey of G 34.3+0.15 (Paper I, Macdonald et al., 1996A&AS..119..333M).