Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Deep HST Study of the Globular Cluster NGC 6397: Reduction Methods   We describe here the reduction methods that we developed to study the
faintest red dwarfs and white dwarfs in an outer field of NGC6397, which was
observed by \hst for 126 orbits in 2005. The particular challenge of this data
set is that the faintest stars are not readily visible in individual exposures,
so special care must be taken to combine the information in all the exposures
in order to identify and measure them. Unfortunately, it is hard to find the
faintest stars without also finding a large number of faint galaxies, so we
developed specialized tools to distinguish between the point-like stars and the
barely resolved galaxies. We found that artificial-star tests, while obviously
necessary for completeness determination, can also play an important role in
helping us optimize our finding and measuring algorithms. Although this paper
focuses on this data set specifically, many of the techniques are new and might
find application in other work, particularly when a large number of images is
available for a single field.

8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
1
The categories of this paper are: cs
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
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The categories of this paper are: cond-mat