Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The XMM-Newton Serendipitous Survey. VI. The X-ray Luminosity Function   We present the X-ray luminosity function of AGN in three energy bands (Soft:
0.5-2 keV, Hard: 2-10 keV and Ultrahard: 4.5-7.5 keV). We have used the XMS
survey along with other highly complete flux-limited deeper and shallower
surveys for a total of 1009, 435 and 119 sources in the Soft, Hard and
Ultrahard bands, respectively. We have modeled the intrinsic absorption of the
Hard and Ultrahard sources (NH function) and computed the intrinsic X-ray
luminosity function in all bands using a Maximum Likelihood fit technique to an
analytical model. We find that the X-ray luminosity function (XLF) is best
described by a Luminosity-Dependent Density Evolution (LDDE) model. Our results
show a good overall agreement with previous results in the Hard band, although
with slightly weaker evolution. Our model in the Soft band present slight
discrepancies with other works in this band, the shape of our present day XLF
being significantly flatter. We find faster evolution in the AGN detected in
the Ultrahard band than those in the Hard band. The fraction of absorbed AGN in
the Hard and Ultrahard bands is dependent on the X-ray luminosity. We find
evidence of evolution of this fraction with redshift in the Hard band but not
in the Ultrahard band, possibly due to the low statistics. Our best-fit XLF
shows that the high-luminosity AGN are fully formed earlier than the less
luminous AGN. The latter sources account for the vast majority of the accretion
rate and mass density of the Universe, according to an anti-hierarchical black
hole growth scenario.

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The categories of this paper are: comp-gas
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The categories of this paper are: atom-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: nlin
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The categories of this paper are: cmp-lg
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The categories of this paper are: acc-phys
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The categories of this paper are: mtrl-th
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The categories of this paper are: alg-geom
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The categories of this paper are: math-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-ph
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The categories of this paper are: stat
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The categories of this paper are: dg-ga
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The categories of this paper are: math
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The categories of this paper are: gr-qc