Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Parking planets in circumbinary discs   The Kepler space mission discovered about a dozen planets orbiting around
binary stars systems. Most of these circumbinary planets lie near their
instability boundaries at about 3 to 5 binary separations. Past attempts to
match these final locations through an inward migration process were only
successful for the Kepler-16 system. Here, we study 10 circumbinary systems and
try to match the final parking locations and orbital parameters of the planets
with a disc driven migration scenario.
  We performed 2D locally isothermal hydrodynamical simulations of circumbinary
discs with embedded planets and followed their migration evolution using
different values for the disc viscosity and aspect ratio. We found that for the
six systems with intermediate binary eccentricities ($0.1 \le e_{bin}\le 0.21$)
the final planetary orbits matched the observations closely for a single set of
disc parameters, specifically a disc viscosity of $\alpha = 10^{-4}$, and an
aspect ratio of $H/r \sim 0.04$. For these systems the planet masses were large
enough to open at least a partial gap in their discs as they approach the
binary, forcing the discs to become circularized and allowing for further
migration towards the binary, leading to good agreement with the observed
planetary orbital parameters.
  For systems with very small or large binary eccentricities the match was not
as good because the very eccentric discs and large inner cavities in these
cases prevented close-in planet migration. In test simulations with higher than
observed planet masses better agreement could be found for those systems.
  The good agreement for 6 out of the 10 modelled systems, where the relative
difference between observed and simulated final planet orbit is $\leq 10\%$,
strongly supports the idea that planet migration in the disc brought the
planets to their present locations.

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The categories of this paper are: cond-mat
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The categories of this paper are: hep-lat
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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: solv-int
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The categories of this paper are: cs
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The categories of this paper are: mtrl-th
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The categories of this paper are: nucl-th
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The categories of this paper are: physics
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The categories of this paper are: quant-ph
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The categories of this paper are: eess
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The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: gr-qc
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The categories of this paper are: chem-ph
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The categories of this paper are: econ