Testing the theory of grain growth and fragmentation by millimeter observations of protoplanetary disks - Astrophysics > Solar and Stellar AstrophysicsReport as inadecuate




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Abstract: Context. Observations at sub-millimeter and mm wavelengths will in the nearfuture be able to resolve the radial dependence of the mm spectral slope incircumstellar disks with a resolution of around a few AU at the distance of theclosest star-forming regions.Aims. We aim to constrain physical models of grain growth and fragmentationby a large sample of sub-mm observations of disks around pre-main sequencestars in the Taurus-Auriga and Ophiuchus star-forming regions.Methods. State-of-the-art coagulation-fragmentation and disk-structure codesare coupled to produce steady-state grain size distributions and to predict thespectral slopes at sub-mm wavelengths.Results. This work presents the first calculations predicting the mm spectralslope based on a physical model of grain growth. Our models can quite naturallyreproduce the observed mm-slopes, but a simultaneous match to the observedrange of flux levels can only be reached by a reduction of the dust mass by afactor of a few up to about 30 while keeping the gas mass of the disk the same.This dust reduction can either be due to radial drift at a reduced rate orduring an earlier evolutionary time otherwise the predicted fluxes wouldbecome too low or due to efficient conversion of dust into larger, unseenbodies.



Author: T. Birnstiel, L. Ricci, F. Trotta, C.P. Dullemond, A. Natta, L. Testi, C. Dominik, T. Henning, C.W. Ormel, A. Zsom

Source: https://arxiv.org/







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