Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Chandra observations of five INTEGRAL sources: new X-ray positions for
  IGR J16393-4643 and IGR J17091-3624   The Chandra High Resolution Camera observed the fields of five hard X-ray
sources in order to help us obtain X-ray coordinates with sub-arcsecond
precision. These observations provide the most accurate X-ray positions known
for IGR J16393-4643 and for IGR J17091-3624. The obscured X-ray pulsar IGR
J16393-4643 lies at R.A. (J2000) = 16:39:05.47, and Dec. = -46:42:13.0 (error
radius of 0.6" at 90% confidence). This position is incompatible with the
previously-proposed counterpart 2MASS J16390535-4642137, and it points instead
to a new counterpart candidate that is possibly blended with the 2MASS star.
The black hole candidate IGR J17091-3624 was observed during its 2011 outburst
providing coordinates of R.A. = 17:09:07.59, and Dec. = -36:24:25.4. This
position is compatible with those of the proposed optical/IR and radio
counterparts, solidifying the source's status as a microquasar. Three targets,
IGR J14043-6148, IGR J16358-4726, and IGR J17597-2201, were not detected. We
obtained 3{\sigma} upper limits of, respectively, 1.7, 1.8, and 1.5 \times
10^-12 erg cm^-2 s^-1 on their 2-10 keV fluxes.

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The categories of this paper are: nucl-th
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The categories of this paper are: econ
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The categories of this paper are: q-alg
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The categories of this paper are: plasm-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: supr-con
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The categories of this paper are: gr-qc
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The categories of this paper are: math-ph
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The categories of this paper are: q-fin
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The categories of this paper are: q-bio
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-th
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The categories of this paper are: nlin