Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Inner dusty regions of protoplanetary discs - I. High resolution
  temperature structure   Our current understanding of the physical conditions in the inner regions of
protoplanetary discs is becoming increasingly challenged by the more detailed
observational and theoretical explorations. Calculation of dust temperature is
one of the key features we strive to understand and a necessary step in image
and flux reconstruction. We explore coexistence of small (0.1mic radius) and
big (2mic radius) dust grains can coexist at distances from the star where
small grains would not survive without big grains shielding them from the
direct starlight. The study required a high resolution radiative transfer
calculation capable of resolving large temperature gradients and disc surface
curvatures caused by dust sublimation. The calculation was also capable of
resolving temperature inversion effect in big grains, where the maximum dust
temperature is at visual optical depth of tau_V~1.5. We also show disc images
and spectra, with disentangled contributions from small and big grains. Big
grains dominate the near IR flux, mainly because of the bright hot inner disc
rim. Small grains populate almost the entire inner disc interior, but appear in
the disc surface at distances 2.2 times larger than the closest distance of big
grains from the star. Nevertheless, small grains can contribute to the image
surface brightness at smaller radii because they are visible below the
optically thin surface defined by stellar heating. Our calculations demonstrate
that the sublimation temperature does not provide a unique boundary condition
for radiative transfer models of optically thick discs. The source of this
problem is the temperature inversion effect, which allows survival of optically
thin configurations of big grains closer to the star than the inner radius of
optically thick disc. Future attempts to derive more realistic multigrain inner
disc models will require the numerical resolution ...

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The categories of this paper are: chem-ph
1
The categories of this paper are: cs
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The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
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The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
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The categories of this paper are: cmp-lg
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The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
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The categories of this paper are: adap-org
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The categories of this paper are: chao-dyn
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The categories of this paper are: econ
2
The categories of this paper are: math
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The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
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The categories of this paper are: eess