Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The (un)resolved X-ray background in the Lockman Hole   Most of the soft and a growing fraction of the harder X-ray background has
been resolved into emission from point sources, yet the resolved fraction above
7 keV has only been poorly constrained. We use ~700 ks of XMM-Newton
observations of the Lockman Hole and a photometric approach to estimate the
total flux attributable to resolved sources in a number of different energy
bands. We find the resolved fraction of the X-ray background to be ~90 per cent
below 2 keV but it decreases rapidly at higher energies with the resolved
fraction above ~7 keV being only ~50 per cent. The integrated X-ray spectrum
from detected sources has a slope of Gamma~1.75, much softer than the Gamma=1.4
of the total background spectrum. The unresolved background component has the
spectral signature of highly obscured AGN.

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The categories of this paper are: math-ph
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The categories of this paper are: patt-sol
1
The categories of this paper are: cs
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: alg-geom
2
The categories of this paper are: math
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The categories of this paper are: eess
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The categories of this paper are: dg-ga
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The categories of this paper are: stat
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The categories of this paper are: gr-qc
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The categories of this paper are: chao-dyn
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The categories of this paper are: ao-sci
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The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph