P. Pinilla, T. Birnstiel, L. Ricci, C. P. Dullemond, A. L. Uribe, L. Testi, A. Natta
In order to explain grain growth to mm sized particles and their retention in
outer regions of protoplanetary disks, as it is observed at sub-mm and mm
wavelengths, we investigate if strong inhomogeneities in the gas density
profiles can slow down excessive radial drift and can help dust particles to
grow. We use coagulation/fragmentation and disk-structure models, to simulate
the evolution of dust in a bumpy surface density profile which we mimic with a
sinusoidal disturbance. For different values of the amplitude and length scale
of the bumps, we investigate the ability of this model to produce and retain
large particles on million years time scales. In addition, we introduced a
comparison between the pressure inhomogeneities considered in this work and the
pressure profiles that come from magnetorotational instability. Using the
Common Astronomy Software Applications ALMA simulator, we study if there are
observational signatures of these pressure inhomogeneities that can be seen
with ALMA. We present the favorable conditions to trap dust particles and the
corresponding calculations predicting the spectral slope in the mm-wavelength
range, to compare with current observations. Finally we present simulated
images using different antenna configurations of ALMA at different frequencies,
to show that the ring structures will be detectable at the distances of the
Taurus Auriga or Ophiucus star forming regions.
View original:
http://arxiv.org/abs/1112.2349
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