Molecular Clouds Chemistry with Mixing
Turbulent motions are observed in molecular clouds which may prevent the achievment of equilibrium chemical abundances. The possibility of mass exchanges between the envelope and the dense cores of a cloud can lead to significant injection of ionized species in dense and UV shielded regions, opening new chemical chanels. We have calculated the steady state abundances of various molecules as a function of the mixing rate. High C/CO ratios and low H 2 O abundances are obtained over a wide range of the mixing rate, pointing to a characteristic mixing time of the order of the free-fall time in cloud cores. This leads to put constraints on the efficiency of clump condensation by gravity alone. As an alternative, preliminary results regarding clump formation and dynamics triggered by radiation field inhomogeneities are also presented.
KeywordsMolecular Cloud Star Formation Rate Monthly Notice Dissociative Recombination Dense Clump
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