Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Modeling the Infrared Extinction toward the Galactic Center   We model the ~1--19$\mum$ infrared (IR) extinction curve toward the Galactic
Center (GC) in terms of the standard silicate-graphite interstellar dust model.
The grains are taken to have a power law size distribution with an exponential
decay above some size. The best-fit model for the GC IR extinction constrains
the visual extinction to be Av~38--42 mag. The limitation of the model, i.e.,
its difficulty in simultaneously reproducing both the steep ~1--3$\mum$ near-IR
extinction and the flat ~3--8$\mum$ mid-IR extinction is discussed. We argue
that this difficulty could be alleviated by attributing the extinction toward
the GC to a combination of dust in different environments: dust in diffuse
regions (characterized by small Rv and steep near-IR extinction), and dust in
dense regions (characterized by large Rv and flat UV extinction).

3
The categories of this paper are: physics
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: eess
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The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
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The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
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The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg