Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A low accretion efficiency of planetesimals formed at planetary gap
  edges   Observations and models of giant planets indicate that such objects are
enriched in heavy elements compared to solar abundances. The prevailing view is
that giant planets accreted multiple Earth masses of heavy elements after the
end of core formation. Such late solid enrichment is commonly explained by the
accretion of planetesimals. Planetesimals are expected to form at the edges of
planetary gaps, and here we address the question of whether these planetesimals
can be accreted in large enough amounts to explain the inferred high heavy
element contents of giant planets. We perform a series of N-body simulations of
the dynamics of planetesimals and planets during the planetary growth phase,
taking into account gas drag as well as the enhanced collision cross-section
caused by the extended envelopes. We consider the growth of Jupiter and Saturn
via gas accretion after reaching the pebble isolation mass and we include their
migration in an evolving disk. We find that the accretion efficiency of
planetesimals formed at planetary gap edges is very low: less than 10% of the
formed planetesimals are accreted even in the most favorable cases, which in
our model corresponds to a few Earth-masses. When planetesimals are assumed to
form beyond the feeding zone of the planets, extending to a few Hill radii from
a planet, accretion becomes negligible. Furthermore, we find that the accretion
efficiency increases when the planetary migration distance is increased and
that the efficiency does not increase when the planetesimal radii are
decreased. Based on these results we conclude that it is difficult to explain
the large heavy element content of giant planets with planetesimal accretion
during the gas accretion phase. Alternative processes most likely are required,
e.g. accretion of vapor deposited by drifting pebbles.

18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
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The categories of this paper are: ao-sci
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The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
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The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
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The categories of this paper are: eess
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The categories of this paper are: funct-an
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The categories of this paper are: cmp-lg