Abstract

Line radiative transfer in C¹⁸O, HCO⁺, and CS lines is considered in a spherically symmetric chemo-dynamical model of a starless core, evolution of which is driven by the ambipolar diffusion. Theoretical line profiles are compared to observational data on the well-known L1544 core, which is one of possible candidates for collapsing protostellar clouds. Dependence of line shapes on model parameters is investigated. It is shown that most important factors determining line shapes are the structure of the cloud envelope and its kinematic properties. Spectral profiles do not change significantly if we vary parameters of the radiation transfer, namely, kinetic temperature and microturbulent velocity, within limits allowed by observations. Comparison between modelled and observed spectra suggests that L1544 has flattened structure and is observed at some inclination. 2D-model is needed to describe the structure of this core properly.