Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The nature of the soft-excess and spectral variability in the Seyfert 1
  galaxy Zw 229.015   We have carried out a systematic analysis of the nearby (z=0.0279) active
galaxy Zw 229.015 using multi-epoch, multi-instrument and deep pointed
observations with XMM-Newton, Suzaku, Swift and NuSTAR. Spectral and temporal
variability are examined in detail on both the long (weeks-to-years) and short
(hours) timescales. A deep Suzaku observation of the source shows two distinct
spectral states; a bright-soft state and a dim-hard state in which changes in
the power law component account for the differences. Partial covering, blurred
reflection and soft Comptonisation models describe the X-ray spectra comparably
well, but the smooth, rather featureless, spectrum may be favouring the soft
Comptonisation scenario. Moreover, independent of the spectral model, the
observed spectral variability is ascribed to the changes in the power law
continuum only and do not require changes in the properties of the absorber or
blurred reflector incorporated in the other scenarios. The multi-epoch
observations between 2009 and 2018 can be described in similar fashion. This
could be understood if the primary emission is originating at a large distance
from a standard accretion disc or if the disc is optically thin and
geometrically thick as recently proposed for Zw 229.015. Our investigation
shows that Zw 229.015 behaves similar to sources like Akn 120 and Mrk 530, that
exhibit a strong soft-excess, but weak Compton hump and Fe K${\alpha}$
emission.

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The categories of this paper are: hep-th
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The categories of this paper are: q-bio
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The categories of this paper are: supr-con
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The categories of this paper are: funct-an
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The categories of this paper are: solv-int
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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: hep-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: physics
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The categories of this paper are: adap-org
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The categories of this paper are: patt-sol
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The categories of this paper are: bayes-an
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The categories of this paper are: plasm-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: nucl-th