Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: CARS: the CFHTLS-Archive-Research Survey; I. Five-band multi-colour data
  from 37 sq. deg. CFHTLS-Wide observations   We present the CFHTLS-Archive-Research Survey (CARS). It is a virtual
multi-colour survey based on public archive images from the CFHT-Legacy-Survey.
Our main scientific interests in CARS are optical searches for galaxy clusters
from low to high redshift and their subsequent study with photometric and
weak-gravitational lensing techniques. As a first step of the project we
present multi-colour catalogues from 37 sq. degrees of the CFHTLS-Wide
component. Our aims are to create astrometrically and photometrically well
calibrated co-added images. Second goal are five-band (u*, g', r', i', z')
multi-band catalogues with an emphasis on reliable estimates for object
colours. These are subsequently used for photometric redshift estimates. The
article explains in detail data processing, multi-colour catalogue creation and
photometric redshift estimation. Furthermore we apply a novel technique, based
on studies of the angular galaxy cross-correlation function, to quantify the
reliability of photo-z's. The accuracy of our high-confidence photo-z sample
(10-15 galaxies per sq. arcmin) is estimated to $\sigma_{\Delta_z/(1+z)}\approx
0.04-0.05$ up to i'<24 with typically only 1-3% outliers. Interested users can
obtain access to our data by request to the authors.

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The categories of this paper are: acc-phys
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The categories of this paper are: eess
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
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The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
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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: funct-an
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The categories of this paper are: mtrl-th
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The categories of this paper are: hep-ph
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The categories of this paper are: comp-gas
2
The categories of this paper are: math
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The categories of this paper are: adap-org
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The categories of this paper are: stat
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The categories of this paper are: nucl-ex