Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High-Resolution X-Ray Spectroscopy of the Galactic Supernova Remnant
  Puppis A with the XMM-Newton RGS   We present high-resolution X-ray spectra of cloud-shock interaction regions
in the eastern and northern rims of the Galactic supernova remnant Puppis A,
using the Reflection Grating Spectrometer onboard the XMM-Newton satellite. A
number of emission lines including K alpha triplets of He-like N, O, and Ne are
clearly resolved for the first time. Intensity ratios of forbidden to resonance
lines in the triplets are found to be higher than predictions by thermal
emission models having plausible plasma parameters. The anomalous line ratios
cannot be reproduced by effects of resonance scattering, recombination, or
inner-shell ionization processes, but could be explained by charge-exchange
emission that should arise at interfaces between the cold/warm clouds and the
hot plasma. Our observations thus provide observational support for
charge-exchange X-ray emission in supernova remnants.

18
The categories of this paper are: econ
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The categories of this paper are: eess
29
The categories of this paper are: funct-an
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The categories of this paper are: nlin
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The categories of this paper are: hep-th
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
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The categories of this paper are: physics
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The categories of this paper are: comp-gas
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The categories of this paper are: gr-qc
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The categories of this paper are: nucl-th
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The categories of this paper are: chem-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: hep-ph
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The categories of this paper are: q-alg
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The categories of this paper are: patt-sol