Non-LTE line formation in clumpy and turbulent molecular clouds

Extending previous work (Albrecht & Kegel 1987, Kegel et al. 1993, Piehler & Kegel 1994), we investigated the formation of interstellar molecular lines in a medium with stochastic density and velocity fluctuations. We solved the full NLTE– problem, i.e. the generalized radiative transfer equation simultaneously with the rate equations, for a 6–level CO molecule and a plane-parallel slab geometry. Our results indicate that accounting for a finite correlation length of both, the density and velocity field, strongly affects the line profile and the line width as well as the intensity ratios of different rotational transitions.