Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: ExploreNEOs I: Description and first results from the Warm Spitzer NEO
  Survey   We have begun the ExploreNEOs project in which we observe some 700 Near Earth
Objects (NEOs) at 3.6 and 4.5 microns with the Spitzer Space Telescope in its
Warm Spitzer mode. From these measurements and catalog optical photometry we
derive albedos and diameters of the observed targets. The overall goal of our
ExploreNEOs program is to study the history of near-Earth space by deriving the
physical properties of a large number of NEOs. In this paper we describe both
the scientific and technical construction of our ExploreNEOs program. We
present our observational, photometric, and thermal modeling techniques. We
present results from the first 101 targets observed in this program. We find
that the distribution of albedos in this first sample is quite broad, probably
indicating a wide range of compositions within the NEO population. Many objects
smaller than one kilometer have high albedos (>0.35), but few objects larger
than one kilometer have high albedos. This result is consistent with the idea
that these larger objects are collisionally older, and therefore possess
surfaces that are more space weathered and therefore darker, or are not subject
to other surface rejuvenating events as frequently as smaller NEOs.

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The categories of this paper are: hep-lat
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The categories of this paper are: stat
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The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
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The categories of this paper are: solv-int
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The categories of this paper are: nlin
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
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The categories of this paper are: econ
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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: ao-sci
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The categories of this paper are: quant-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: dg-ga