Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Trojan Color Conundrum   The Trojan asteroids of Jupiter and Neptune are likely to have been captured
from original heliocentric orbits in the dynamically excited ("hot") population
of the Kuiper belt. However, it has long been known that the optical color
distributions of the Jovian Trojans and the hot population are not alike. This
difference has been reconciled with the capture hypothesis by assuming that the
Trojans were resurfaced (for example, by sublimation of near-surface volatiles)
upon inward migration from the Kuiper belt (where blackbody temperatures are
$\sim$40 K) to Jupiter's orbit ($\sim$125 K). Here, we examine the optical
color distribution of the \textit{Neptunian} Trojans using a combination of new
optical photometry and published data. We find a color distribution that is
statistically indistinguishable from that of the Jovian Trojans but unlike any
sub-population in the Kuiper belt. This result is puzzling, because the
Neptunian Trojans are very cold (blackbody temperature $\sim$50 K) and a
thermal process acting to modify the surface colors at Neptune's distance would
also affect the Kuiper belt objects beyond, where the temperatures are nearly
identical. The distinctive color distributions of the Jovian and Neptunian
Trojans thus present us with a conundrum: they are very similar to each other,
suggesting either capture from a common source or surface modification by a
common process. However, the color distributions differ from any plausible
common source population, and there is no known modifying process that could
operate equally at both Jupiter and Neptune.

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The categories of this paper are: quant-ph
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The categories of this paper are: supr-con
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The categories of this paper are: q-fin
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The categories of this paper are: q-bio
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The categories of this paper are: patt-sol
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The categories of this paper are: q-alg
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The categories of this paper are: alg-geom
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The categories of this paper are: chao-dyn
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: solv-int
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The categories of this paper are: stat
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The categories of this paper are: plasm-ph
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The categories of this paper are: adap-org
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The categories of this paper are: cs