Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: New Perspectives on the X-ray Emission of HD 104237 and Other Nearby
  Herbig Ae/Be Stars from XMM-Newton and Chandra   We present new X-ray observations of the nearby Herbig Ae star HD 104237 (=
DX Cha) with XMM-Newton, whose objective is to clarify the origin of the
emission. Several X-ray emission lines are clearly visible in the CCD spectra,
including the high-temperature Fe K-alpha complex. The emission can be
accurately modeled as a multi-temperature thermal plasma with cool (kT < 1 keV)
and hot (kT > 3 keV) components. The presence of a hot component is compelling
evidence that the X-rays originate in magnetically confined plasma, either in
the Herbig star itself or in the corona of an as yet unseen late-type
companion. The X-ray temperatures and luminosity (log Lx = 30.5 ergs/s) are
within the range expected for a T Tauri companion, but high resolution Chandra
and HST images constrain the separation of a putative companion to less than 1
arcsec. We place these new results into broader context by comparing the X-ray
and bolometric luminosities of a sample of nearby Herbig stars with those of T
Tauri stars and classical main-sequence Be stars. We also test the predictions
of a model that attributes the X-ray emission of Herbig stars to magnetic
activity that is sustained by a shear-powered dynamo.

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The categories of this paper are: eess
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The categories of this paper are: solv-int
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The categories of this paper are: chem-ph
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The categories of this paper are: econ
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The categories of this paper are: patt-sol
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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: nucl-th
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The categories of this paper are: physics
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The categories of this paper are: q-fin
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The categories of this paper are: mtrl-th
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The categories of this paper are: atom-ph
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The categories of this paper are: funct-an
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The categories of this paper are: comp-gas
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The categories of this paper are: math-ph
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The categories of this paper are: hep-th