Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Broadband X-ray Spectral Study of Ultra-luminous X-ray Source M81 X--6   Ultra-luminous X-ray sources (ULXs) are a class of extra-galactic,
point-like, off-nuclear X-ray sources with X-ray luminosity from $\sim
10^{39}$~erg s$^{-1}$ to $10^{41}$~erg s$^{-1}$. We investigated the temporal
and broadband X-ray spectral properties of the ULX M81~X--6 using simultaneous
\textit{Suzaku} and \textit{NuSTAR} observations. To understand the nature of
the source, we searched for pulsating signals from the source using the
\textit{NuSTAR} observation. However, we failed to identify any strong
pulsating signals from the source. Alternatively, the broadband spectral
modelling with accreting magnetic neutron star continuum model provides a
statistically acceptable fit, and the inferred spectral parameters and X-ray
colours are consistent with other pulsating ULXs. Thus, our analysis suggests
that M81~X--6 is another candidate ULX pulsar.

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The categories of this paper are: math
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The categories of this paper are: mtrl-th
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The categories of this paper are: supr-con
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The categories of this paper are: physics
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The categories of this paper are: hep-th
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The categories of this paper are: eess
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The categories of this paper are: q-bio
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The categories of this paper are: cond-mat
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The categories of this paper are: adap-org
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The categories of this paper are: nucl-th
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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: quant-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: patt-sol
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The categories of this paper are: nucl-ex