Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dust opacity variations in the pre-stellar core L1544   Context: The study of dust emission at millimeter wavelengths is important to
shed light on the dust properties and physical structure of pre-stellar cores,
the initial conditions in the process of star and planet formation. Aims: Using
two new continuum facilities, AzTEC at the LMT and MUSTANG-2 at the GBO, we aim
to detect changes in the optical properties of dust grains as a function of
radius for the well-known pre-stellar core L1544. Methods: We determine the
emission profiles at 1.1 and 3.3 mm and examine whether they can be reproduced
in terms of the current best physical models for L1544. We also make use of
various tools to determine the radial distributions of the density,
temperature, and the dust opacity in a self-consistent manner. Results: We find
that our observations cannot be reproduced without invoking opacity variations.
With the new data, new temperature and density profiles, as well as opacity
variations across the core, have been derived. The opacity changes are
consistent with the expected variations between uncoagulated bare grains,
toward the outer regions of the core, and grains with thick ice mantles, toward
the core center. A simple analytical grain growth model predicts the presence
of grains of ~3-4 um within the central 2000 au for the new density profile.

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The categories of this paper are: nucl-th
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The categories of this paper are: math-ph
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
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The categories of this paper are: acc-phys
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
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The categories of this paper are: alg-geom
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The categories of this paper are: nucl-ex
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The categories of this paper are: bayes-an