Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Ultra Luminous X-ray sources in the High Velocity System of NGC 1275   We report the results of a study of X-ray point sources coincident with the
High Velocity System (HVS) projected in front of NGC 1275. A very deep X-ray
image of the core of the Perseus cluster made with the Chandra Observatory has
been used. We find a population of Ultra-Luminous X-ray sources (ULX; 7 sources
with LX [0.5-7 keV] > 7x10^39 erg/s). As with the ULX populations in the
Antennae and Cartwheel galaxies, those in the HVS are associated with a region
of very active star formation. Several sources have possible optical
counterparts found on HST images, although the X-ray brightest one does not.
Absorbed power-law models fit the X-ray spectra, with most having a photon
index between 2 and 3.

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The categories of this paper are: stat
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
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The categories of this paper are: econ
28
The categories of this paper are: alg-geom
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The categories of this paper are: nucl-ex
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The categories of this paper are: eess
5
The categories of this paper are: gr-qc
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The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
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The categories of this paper are: hep-ex
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The categories of this paper are: bayes-an
3
The categories of this paper are: physics
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The categories of this paper are: hep-lat