Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Proving strong magnetic fields near to the central black hole in the
  quasar PG0043+039 via cyclotron lines   The optical luminous quasar PG0043+039 has not been detected before in deep
X-ray observations indicating the most extreme optical-to-X-ray slope index
${\alpha}_{ox}$ of all quasars. This study aims to detect PG0043+039 in a deep
X-ray exposure. Furthermore, we wanted to check out whether this object shows
specific spectral properties in other frequency bands. We took deep X-ray
(XMM-Newton), far-ultraviolet (HST), and optical (HET, SALT telescopes) spectra
of PG0043+039 simultaneously in July 2013. We just detected PG0043+039 in our
deep X-ray exposure. The steep ${\alpha}_{ox} = -2.37 {\pm} 0.05$ gradient is
consistent with an unusual steep gradient $F_{\nu} {\sim} {\nu}^{\alpha}$ with
${\alpha} = -2.67 {\pm} 0.02$ seen in the UV/far-UV continuum. The optical/UV
continuum flux has a clear maximum near 2500 {\AA}. The UV spectrum is very
peculiar because it shows broad humps in addition to known emission lines. A
modeling of these observed humps with cyclotron lines can explain their
wavelength positions, their relative distances, and their relative intensities.
We derive plasma temperatures of T ${\sim}$ 3keV and magnetic field strengths
of B ${\sim}$ 2 ${\times} 10^8$ G for the line-emitting regions close to the
black hole.

2
The categories of this paper are: math
23
The categories of this paper are: solv-int
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The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
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The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-lat
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The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
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The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-th