Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Explaining temporal variations in the jet position angle of the blazar
  OJ 287 using its binary black hole central engine model   The bright blazar OJ 287 is the best-known candidate for hosting a
supermassive black hole binary system. It inspirals due to the emission of
nanohertz gravitational waves (GWs). Observations of historical and predicted
quasi-periodic high-brightness flares in its century-long optical lightcurve,
allow us to determine the orbital parameters associated with the binary black
hole (BBH) central engine. In contrast, the radio jet of OJ 287 has been
covered with Very Long Baseline Interferometry (VLBI) observations for only
about $30$ years and these observations reveal that the position angle (PA) of
the jet exhibits temporal variations at both millimetre and centimetre
wavelengths. Here we associate the observed PA variations in OJ 287 with the
precession of its radio jet. In our model, the evolution of the jet direction
can be associated either with the primary black hole (BH) spin evolution or
with the precession of the angular momentum direction of the inner region of
the accretion disc. Our Bayesian analysis shows that the BBH central engine
model, primarily developed from optical observations, can also broadly explain
the observed temporal variations in the radio jet of OJ 287 at frequencies of
86, 43, and 15 GHz. Ongoing Global mm-VLBI Array (GMVA) observations of OJ 287
have the potential to verify our predictions for the evolution of its $86$ GHz
PA values. Additionally, thanks to the extremely high angular resolution that
the Event Horizon Telescope (EHT) can provide, we explore the possibility to
test our BBH model through the detection of the jet in the secondary black
hole.

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The categories of this paper are: cmp-lg
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The categories of this paper are: q-fin
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The categories of this paper are: mtrl-th
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The categories of this paper are: physics
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The categories of this paper are: math
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The categories of this paper are: patt-sol
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The categories of this paper are: eess
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The categories of this paper are: econ
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The categories of this paper are: nucl-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
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The categories of this paper are: alg-geom
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: solv-int