Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Radio and X-ray variability of Young Stellar Objects in the Coronet
  Cluster   The Coronet Cluster in the nearby R CrA dark cloud offers the rare
opportunity to study at least four "class I" protostellar sources as well as
one candidate "class 0" source, a Herbig Ae star, and a candidate brown dwarf
within a few square arcminutes - most of them detected at radio- and X-ray
wavelengths. These sources were observed with the Very Large Array (VLA) at
3.5cm on nine occasions in 1998, spread over nearly four months. The source IRS
5, earlier shown to emit circularly polarized radio emission, was observed to
undergo a flux increase accompanied by changes in its polarization properties.
Comparison with VLA measurements taken in January 1997 allows for some analysis
of longer-term variability. In addition to this radio monitoring, we analyze
archival Chandra and XMM-Newton X-ray data of these sources. Three class I
protostars are bright enough for X-ray spectroscopy, and we perform a
variability analysis for these sources, covering a total of 154 ksec spread
over more than two and a half years. Also in X-rays, IRS 5 shows the most
pronounced variability, whilst the other two class I protostars IRS 1 and IRS 2
have more stable emission. X-ray data is also analyzed for the recently
identified candidate class 0 source IRS 7E, which shows strong variability as
well as for the Herbig Ae star R CrA for which we find extremely hot
X-ray-emitting plasma. For IRS 1,2 and 5, the hydrogen column densities derived
from the X-ray spectra are at about half the values derived with near-infrared
techniques, a situation similar to what has been observed towards some other
young stellar objects.

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The categories of this paper are: math-ph
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The categories of this paper are: econ
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The categories of this paper are: eess
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The categories of this paper are: cond-mat
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The categories of this paper are: physics
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The categories of this paper are: funct-an
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The categories of this paper are: ao-sci
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The categories of this paper are: solv-int
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-th
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The categories of this paper are: chem-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: cs
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The categories of this paper are: hep-ex
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The categories of this paper are: math
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The categories of this paper are: comp-gas