Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The electron temperature of the inner halo of the Planetary Nebula NGC
  6543   We investigate the electron temperature of the inner halo and nebular core
regions of NGC 6543, using archival Hubble Space Telescope (HST) Wide Field
Planetary Camera 2 (WFPC2) images taken through narrow band [O III] filters.
Balick et al. (2001) showed that the inner halo consists of a number of
spherical shells. We find the temperature of this inner halo to be much higher
(~15000 K) than that of the bright core nebula (~8500 K). Photo-ionization
models indicate that hardening of the UV radiation from the central star cannot
be the main source of the higher temperature in the halo region. Using a
radiation hydrodynamic simulation, we show that mass loss and velocity
variations in the AGB wind can explain the observed shells, as well as the
higher electron temperature.

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The categories of this paper are: hep-lat
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The categories of this paper are: funct-an
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The categories of this paper are: cmp-lg
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The categories of this paper are: quant-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: physics
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The categories of this paper are: chao-dyn
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-bio
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The categories of this paper are: hep-ex
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The categories of this paper are: math-ph
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The categories of this paper are: stat
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The categories of this paper are: eess
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The categories of this paper are: bayes-an
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The categories of this paper are: q-alg
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The categories of this paper are: atom-ph