Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spitzer 70-micron Source Counts in GOODS-North   We present ultra-deep Spitzer 70-micron observations of GOODS-North. For the
first time, the turn-over in the 70-micron Euclidean-normalized differential
source counts is observed. We derive source counts down to a flux density of
1.2mJy. From the measured source counts and fluctuation analysis, we estimate a
power-law approximation of the faint 70-micron source counts of dN/dS
proportional to S^{-1.6}, consistent with that observed for the faint 24-micron
sources. An extrapolation of the 70-micron source counts to zero flux density
implies a total extragalactic background light (EBL) of 7.4+/-1.9 nW m^{-2}
sr^{-1}. The source counts above 1.2mJy account for about 60% of the estimated
EBL. From fluctuation analysis, we derive a photometric confusion level of
sigma_c = 0.30+/-0.15 mJy (q=5) for the Spitzer 70-micron band.

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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: cmp-lg
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The categories of this paper are: patt-sol
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The categories of this paper are: math-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: adap-org
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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: nlin
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The categories of this paper are: math
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The categories of this paper are: alg-geom
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The categories of this paper are: physics
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The categories of this paper are: econ
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The categories of this paper are: comp-gas
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The categories of this paper are: quant-ph