Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An X-ray Outburst from the Rapidly Accreting Young Star That Illuminates
  McNeil's Nebula   Young, low-mass stars are luminous X-ray sources whose powerful X-ray flares
may exert a profound influence over the process of planet formation. The origin
of such emission is uncertain. Although many or perhaps most recently formed,
low-mass stars emit X-rays as a consequence of solar-like coronal activity, it
has also been suggested that X-ray emission may be a direct result of mass
accretion onto the forming star. Here we report X-ray imaging spectroscopy
observations which reveal a factor ~50 increase in the X-ray flux from a young
star that is presently undergoing a spectacular optical/IR outburst. The
outburst is thought to be due to the sudden onset of a phase of rapid
accretion. The coincidence of a surge in X-ray brightness with the optical/IR
eruption demonstrates that strongly enhanced high-energy emission from young
stars can occur as a consequence of high accretion rates. We suggest that such
accretion- enhanced X-ray emission from erupting young stars may be
short-lived, because intense star-disk magnetospheric interactions are quenched
rapidly by the subsequent accretion flood.

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The categories of this paper are: eess
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
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The categories of this paper are: nlin
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The categories of this paper are: dg-ga
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The categories of this paper are: comp-gas
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
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The categories of this paper are: plasm-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: math
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The categories of this paper are: stat
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The categories of this paper are: q-alg
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The categories of this paper are: alg-geom