Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Chasing the Identification of ASCA Galactic Objects (ChIcAGO) - An X-ray
  Survey of Unidentified Sources in the Galactic Plane I: Source Sample and
  Initial Results   We present the Chasing the Identification of ASCA Galactic Objects (ChIcAGO)
survey, which is designed to identify the unknown X-ray sources discovered
during the ASCA Galactic Plane Survey (AGPS). Little is known about most of the
AGPS sources, especially those that emit primarily in hard X-rays (2-10 keV)
within the F_x ~ 10^-13 to 10^-11 erg cm^-2 s^-1 X-ray flux range. In ChIcAGO,
the subarcsecond localization capabilities of Chandra have been combined with a
detailed multi-wavelength follow-up program, with the ultimate goal of
classifying the >100 unidentified sources in the AGPS. Overall to date, 93
unidentified AGPS sources have been observed with Chandra as part of the
ChIcAGO survey. A total of 253 X-ray point sources have been detected in these
Chandra observations within 3' of the original ASCA positions. We have
identified infrared and optical counterparts to the majority of these sources,
using both new observations and catalogs from existing Galactic plane surveys.
X-ray and infrared population statistics for the X-ray point sources detected
in the Chandra observations reveal that the primary populations of Galactic
plane X-ray sources that emit in the F_x ~ 10^-13 to 10^-11 erg cm^-2 s^-1 flux
range are active stellar coronae, massive stars with strong stellar winds that
are possibly in colliding-wind binaries, X-ray binaries, and magnetars. There
is also a fifth population that is still unidentified but, based on its X-ray
and infrared properties, likely comprise partly of Galactic sources and partly
of active galactic nuclei.

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The categories of this paper are: mtrl-th
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: q-fin
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The categories of this paper are: cs
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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: comp-gas
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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: hep-ph
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The categories of this paper are: nlin
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The categories of this paper are: stat
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-ex