Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Mid-Infrared Observations of Planetary Nebulae detected in the GLIMPSE
  3D Survey   We present mapping, profiles and photometry for 24 planetary nebulae (PNe)
detected in the GLIMPSE 3D mid-infrared (MIR) survey of the Galactic plane. The
PNe show many of the properties observed in previous studies of these sources,
including evidence for longer wave emission from outside of the ionised zones,
a likely consequence of emission from polycyclic aromatic hydrocarbons (PAHs)
within the nebular photo-dissociation regimes (PDRs). We also note variations
in 5.8/4.5 and 8.0/4.5 microns flux ratios with distance from the nuclei;
present evidence for enhanced MIR emission in the halos of the sources; and
note evidence for variations in colour with nebular evolution.

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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-lat
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The categories of this paper are: supr-con
3
The categories of this paper are: physics
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The categories of this paper are: eess
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The categories of this paper are: comp-gas
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The categories of this paper are: alg-geom
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The categories of this paper are: ao-sci
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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: solv-int
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The categories of this paper are: bayes-an
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The categories of this paper are: cs
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The categories of this paper are: q-fin
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The categories of this paper are: gr-qc
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The categories of this paper are: funct-an