Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The deepest image of the Universe at a wavelength of 15 microns   We present photometry, photometric redshifts and extra galactic number counts
for ultra deep 15 micron mapping of the gravitational lensing cluster Abell
2218 (A2218), which is the deepest image taken by any facility at this
wavelength. This data resolves the cosmic infrared background (CIRB) beyond the
80% that blank field AKARI surveys aim to achieve. To gain an understanding of
galaxy formation and evolution over the age of the Universe a necessary step is
to fully resolve the CIRB, which represents the dust-shrouded cosmic star
formation history. Observing through A2218 gives magnifications of up to a
factor of 10, thus allowing the sampling of a more representative spread of
high redshift galaxies, which comprise the bulk of the CIRB. 19 pointed
observations were taken by AKARIs IRC MIR-L channel, and a final combined image
with an area of 122.3 square arcminutes and effective integration time of 8460
seconds was achieved. The 5 sigma sensitivity limit is estimated at 41.7 uJy.
An initial 5 sigma catalogue of 565 sources was extracted giving 39 beams per
source, which shows the image is confusion limited. Our 15 micron number counts
show strong evolution consistent with galaxy evolution models that incorporate
downsizing in star formation.

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The categories of this paper are: plasm-ph
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The categories of this paper are: q-fin
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The categories of this paper are: econ
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The categories of this paper are: funct-an
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-th
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The categories of this paper are: hep-ex
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The categories of this paper are: solv-int
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The categories of this paper are: alg-geom
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The categories of this paper are: math
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The categories of this paper are: ao-sci
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The categories of this paper are: chem-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: comp-gas
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The categories of this paper are: supr-con
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The categories of this paper are: chao-dyn