Abstract

The dust continuum and molecular distributions observed on the sky plane always show irregular shapes of molecular clouds. However, it is hard to directly reproduce the observed distributions using symmetrical models. In this work, for the first time, we present a three-dimensional (3D) gas-grain chemical simulation using an irregular 3D density structure derived by the Abel inversion taking the starless core L1544 as an example. We found that most (∼70 per cent) of the observed features (molecular distributions, peak positions, and column density values of 16 species) can be reproduced directly. The previously reached conclusion of non-uniform illumination at C3H2 peak is confirmed as the contribution from the gas component with density of a few 104 cm-3 at distance of ∼3000–8000 au from the core centre along the line of sight.