Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Chandra Observation of the Magellanic Cloud Supernova Remnant 0454-672
  in N9   A Chandra observation has defined the extent of the SNR B 0454-692 in the LMC
H II region N9. The remnant has dimension 2.3" x 3.6" and is elongated in the
NS direction. The brightest emission comes from a NS central ridge which
includes three bright patches. There is good agreement between X-ray and [O
III] and [S II] morphology. The remnant is old enough so that optical data give
more information about dynamics than do the X-ray data. The SN energy release
was >= 4 x 10^50 ergs and the age is ~3 x 10^4 years. There are several
unresolved sources nearby but none are clearly associated with the remnant. The
X-ray spectrum is soft and indicates enhanced Fe abundance in the central
region, consistent with a Type Ia SN origin, but a Type II origin cannot be
ruled out.

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The categories of this paper are: eess
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The categories of this paper are: q-bio
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The categories of this paper are: q-fin
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The categories of this paper are: hep-lat
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The categories of this paper are: bayes-an
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The categories of this paper are: physics
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-ph
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The categories of this paper are: math
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The categories of this paper are: cmp-lg
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The categories of this paper are: ao-sci
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-ex
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The categories of this paper are: nucl-ex
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The categories of this paper are: atom-ph
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The categories of this paper are: cond-mat