Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Pluto-Charon Sonata III. Growth of Charon from a Circum-Pluto Ring of
  Debris   Current theory considers two options for the formation of the Pluto-Charon
binary (Canup 2005, 2011; Desch 2015). In the `hit-and-run' model, a lower mass
projectile barely hits the more massive Pluto, kicks up some debris, and
remains bound to Pluto (see also Asphaug et al. 2006). In a `graze-and-merge'
scenario, the projectile ejects substantial debris as it merges with Pluto (see
also Canup 2001). To investigate the graze-and-merge idea in more detail, we
consider the growth of Charon-mass objects within a circum-Pluto ring of
solids. Numerical calculations demonstrate that Charon analogs form rapidly
within a swarm of planetesimals with initial radii of 145-230 km. On time
scales of roughly 30-100 days, newly-formed Charon analogs have semimajor axes,
a = 5-6 Pluto radii, and orbital eccentricities, e = 0.1-0.3, similar to Charon
analogs that remain bound after hit-and-run collisions with Pluto. Although the
early growth of Charon analogs generates rings of small particles at a = 50-275
Pluto radii, ejection of several 145-230 km leftovers by the central
Pluto-Charon binary removes these small solids in 10-100 yr. Simple estimates
suggest small particles might survive the passage of 10-20 km objects ejected
by the central binary. Our results indicate that the Pluto-Charon circumbinary
satellite system was not formed by a graze-and-merge impact when the formation
of Charon within a circum-Pluto disk leads to the ejection of several 100-200
km particles through the orbital plane of the Pluto-Charon binary. If a growing
Charon ejects only much smaller particles, however, graze-and-merge impacts are
a plausible formation channel for the Pluto-Charon binary and an ensemble of
small, circumbinary satellites.

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The categories of this paper are: gr-qc
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The categories of this paper are: stat
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The categories of this paper are: comp-gas
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The categories of this paper are: chem-ph
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The categories of this paper are: econ
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The categories of this paper are: nucl-ex
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The categories of this paper are: physics
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The categories of this paper are: acc-phys
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The categories of this paper are: q-alg
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The categories of this paper are: funct-an
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The categories of this paper are: bayes-an
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The categories of this paper are: q-fin
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The categories of this paper are: supr-con
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The categories of this paper are: ao-sci
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The categories of this paper are: eess
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The categories of this paper are: hep-ph