Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Black hole mass and binary model for BL Lac object OJ 287   Recent intensive observations of the BL Lac object OJ 287 raise a lot of
questions on the models of binary black holes, processing jets, rotating
helical jets and thermal instability of slim accretion disks. After carefully
analyzing their radio flux and polarization data, Valtaoja et al.
(\cite{valtaoja00}) propose a new binary model. Based on the black hole mass of
$4 \times 10^8 {\rm M_\odot}$ estimated with the tight correlations of the
black hole masses and the bulge luminosity or central velocity dispersion of
host galaxies, we computed the physical parameters of the new binary scenario.
The impact of the secondary on the accretion disk around the primary black hole
causes strong shocks propagating inwards and outwards, whose arrival at the jet
roots is identified with the rapid increase of optical polarization and the
large change of polarization angle at about 0.30 yr after the first main
optical flare. An increase of optical polarization, a large rotation of
positional angle and a small synchrotron flare at 2007.05 between the optical
outbursts at 2006.75 and 2007.89 are expected by the model. With the estimated
parameters, we predicated an increase of $\gamma$-ray flux appearing about 5
days after the first optical/IR peak, which is consistent with the EGRET
observations.

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The categories of this paper are: q-fin
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The categories of this paper are: adap-org
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The categories of this paper are: mtrl-th
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The categories of this paper are: ao-sci
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The categories of this paper are: cmp-lg
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The categories of this paper are: q-bio
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The categories of this paper are: nlin
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The categories of this paper are: patt-sol
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The categories of this paper are: physics
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: atom-ph
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The categories of this paper are: econ
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-th