Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Peculiar Extended X-ray Emission around the "Radio-Loud" Black Hole
  Candidate 1E1740.7-2942   We present the discovery of peculiar extended X-ray emission around
1E1740.7-2942, a black hole candidate that is known to produce prominent,
persistent radio jets. The data was obtained with the High-Energy Transmission
Grating Spectrometer (HETGS) aboard the Chandra X-ray Observatory. The
zeroth-order image reveals an elongated feature about 3" in length that is
roughly perpendicular to the radio lobes (or jets). The feature is roughly
symmetric about the point source. It is spatially resolved in the long
direction but not in the short direction.
  The position of 1E1740.7-2942 was determined with a statistical accuracy of
\~0.06" in the right ascension and ~0.04" in the declination, thanks to
Chandra's unprecedented spatial resolution. It is about 0.6" from the radio
position but the difference is well within the uncertainty in the absolute
aspect solutions of the observation. The dispersed HETGS spectra of
1E1740.7-2942 show evidence for the presence of weak, narrow emission lines,
although the statistics are quite limited. We discuss possible origins of the
extended emission and the implications of the emission lines.

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The categories of this paper are: nucl-ex
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The categories of this paper are: adap-org
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The categories of this paper are: solv-int
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The categories of this paper are: math-ph
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The categories of this paper are: math
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The categories of this paper are: hep-ex
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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: gr-qc
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The categories of this paper are: dg-ga
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The categories of this paper are: atom-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: funct-an
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The categories of this paper are: cmp-lg
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The categories of this paper are: cs
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The categories of this paper are: chem-ph