Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Chandra Observations of Eight Sources Discovered by INTEGRAL   We report on 0.3-10 keV observations with the Chandra X-ray Observatory of
eight hard X-ray sources discovered within 8 degrees of the Galactic plane by
the INTEGRAL satellite. The short (5 ks) Chandra observations of the IGR source
fields have yielded very likely identifications of X-ray counterparts for three
of the IGR sources: IGR J14091-6108, IGR J18088-2741, and IGR J18381-0924. The
first two have very hard spectra in the Chandra band that can be described by a
power-law with photon indices of Gamma = 0.6+/-0.4 and -0.7(+0.4)(-0.3),
respectively (90% confidence errors are given), and both have a unique near-IR
counterpart consistent with the Chandra position. IGR J14091-6108 also displays
a strong iron line and a relatively low X-ray luminosity, and we argue that the
most likely source type is a Cataclysmic Variable (CV), although we do not
completely rule out the possibility of a High Mass X-ray Binary. IGR
J18088-2741 has an optical counterpart with a previously measured 6.84 hr
periodicity, which may be the binary orbital period. We also detect five cycles
of a possible 800-950 s period in the Chandra light curve, which may be the
compact object spin period. We suggest that IGR J18088-2741 is also most likely
a CV. For IGR J18381-0924, the spectrum is intrinsically softer with Gamma =
1.5(+0.5)(-0.4), and it is moderately absorbed, nH = (4+/-1)e22 cm-2. There are
two near-IR sources consistent with the Chandra position, and they are both
classified as galaxies, making it likely that IGR J18381-0924 is an Active
Galactic Nucleus (AGN). For the other five IGR sources, we provide lists of
nearby Chandra sources, which may be used along with further observations to
identify the correct counterparts, and we discuss the implications of the low
inferred Chandra count rates for these five sources.

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The categories of this paper are: hep-th
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The categories of this paper are: patt-sol
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The categories of this paper are: acc-phys
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The categories of this paper are: hep-lat
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The categories of this paper are: plasm-ph
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The categories of this paper are: q-alg
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The categories of this paper are: cond-mat
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The categories of this paper are: ao-sci
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The categories of this paper are: nucl-ex
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The categories of this paper are: econ
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The categories of this paper are: alg-geom
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The categories of this paper are: bayes-an
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The categories of this paper are: comp-gas
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The categories of this paper are: supr-con
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The categories of this paper are: nucl-th
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The categories of this paper are: gr-qc