Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ultra Luminous X-ray sources - new distance indicators?   In this paper we fit the NuSTAR and XMM-Newton data of three sources:
NGC7793~P13, NGC5907~ULX1, and Circinus~ULX5. Our single model contains
emission form non-spherical system: neutron star plus accretion disk directed
towards observer. We obtained the very good fit with the reduced $\chi^2$ per
degree of freedom equal 1.08 for P13, 1.01 for ULX1, and 1.14 for ULX5.The
normalization of our model constrains the distance to the source. The resulting
distances are $D=3.41^{+0.11}_{-0.10}$, $6.55_{-0.81}^{+0.69}$ and
$2.60^{+0.05}_{-0.03}$~Mpc for P13, ULX1 and ULX5 respectively. The distances
to P13 and ULX5 are in perfect agreement with previous distance measurements to
their host galaxies. Our results confirm that P13, ULX1 and ULX5 may contain
central hot neutron star. When the outgoing emission is computed by integration
over the emitting surface and successfully fitted to the data, then the
resulting model normalization is the direct distance indicator.

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The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
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The categories of this paper are: solv-int
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The categories of this paper are: bayes-an
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The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: eess
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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: chao-dyn
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The categories of this paper are: cond-mat
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The categories of this paper are: funct-an
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The categories of this paper are: hep-lat