Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Heavy-element Content Trend of Planets: A Tracer of their Formation
  Sites   Identification of the main planet formation site is fundamental to
understanding how planets form and migrate to the current locations. We
consider the heavy-element content trend of observed exoplanets derived from
improved measurements of mass and radius, and explore how this trend can be
used as a tracer of their formation sites. Using gas accretion recipes obtained
from detailed hydrodynamical simulations, we confirm that the disk-limited gas
accretion regime is most important for reproducing the heavy-element content
trend. Given that such a regime is specified by two characteristic masses of
planets, we compute these masses as a function of the distance ($r$) from the
central star, and then examine how the regime appears in the mass-semimajor
axis diagram. Our results show that a plausible solid accretion region emerges
at $r \simeq 0.6$ au and expands with increasing $r$, using the conventional
disk model. Given that exoplanets that possess the heavy-element content trend
distribute currently near their central stars, our results imply the importance
of planetary migration that would occur after solid accretion onto planets
might be nearly completed at $r \geq 0.6$ au. Self-consistent simulations would
be needed to verify the predictions herein.

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The categories of this paper are: supr-con
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The categories of this paper are: gr-qc
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The categories of this paper are: nucl-th
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The categories of this paper are: math-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-ex
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The categories of this paper are: alg-geom
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The categories of this paper are: bayes-an
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The categories of this paper are: funct-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-alg
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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: solv-int
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The categories of this paper are: chem-ph
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The categories of this paper are: cmp-lg