Dust coagulation in dense molecular clouds: the formation of fluffy aggregates

Dust extinction observations and the calculation of gas-dust dynamics indicate that in dense clumps of molecular clouds dust grains coagulate efficiently. We set up a detailed model for the dust coagulation process in dense cores of molecular clouds without beginning star formation. We took into account the effects of thermal, turbulent, gravitational motion, motion from incidential particle asymmetries, grain rotation, charges, and the accretion of molecules onto the particles. For most effects, we developed new formalisms. For the first time, we explicitly considered the irregularity and changing fluffiness of the clusters produced in the coagulation process. The basis for this treatment was an independent numerical simulation of the structure of such aggregates