Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Implications of a possible 23 day periodicity for binary black hole
  models in Mkn~501   We investigate the implications of a massive binary system in the centre of
the gamma-ray blazar Mkn~501 and show that the periodical behaviour recently
observed in the TeV and X-ray lightcurves may possibly be related to the
orbital motion of the relativistic jet emerging from the less massive black
hole. For the special relativistic jet properties inferred from emission
models, we derive an intrinsic orbital period of $(6-14)$ yrs and a
centre-of-mass distance of $(2.0-3.5) \times 10^{16}$ cm. If the binary is very
close with a separation of the order of that for which gravitational radiation
becomes dominant, we find a maximum primary mass of $\sim 10^8 M_{\sun}$ and a
corresponding secondary mass in the range of $\sim (4-42)\times 10^6 M_{\sun}$
depending on the intrinsic jet properties. Such values are in line with the
black hole masses expected from merger scenarios.

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The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
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The categories of this paper are: cs
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
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The categories of this paper are: gr-qc