Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Large-Scale Extinction Map of the Galactic Bulge from the MACHO
  Project Photometry   We present a (V-R)-based reddening map of about 43 square degrees of the
Galactic bulge/bar. The map is constructed using template image photometry from
the MACHO microlensing survey, contains 9717 resolution elements, and is based
on (V-R)-color averages of the entire color-magnitude diagrams (CMDs) in 4 by 4
arc-minute tiles. The conversion from the observed color to the reddening
follows from an assumption that CMDs of all bulge fields would look similar in
the absence of extinction. Consequently, the difference in observed color
between various fields originates from varying contribution of the disk
extinction summed along different lines of sight. We check that our (V-R)
colors correlate very well with infrared and optical reddening maps. We show
that a dusty disk obeying a cosec|b| extinction law, E(V-R) = 0.0274 cosec|b|,
provides a good approximation to the extinction toward the MACHO bulge/bar
fields. The large-scale (V-R)-color and visual extinction map presented here is
publicly available in the electronic edition of the Journal and on the World
Wide Web.

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The categories of this paper are: hep-th
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The categories of this paper are: patt-sol
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The categories of this paper are: alg-geom
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The categories of this paper are: nucl-th
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The categories of this paper are: math-ph
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The categories of this paper are: physics
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The categories of this paper are: stat
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The categories of this paper are: cond-mat
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The categories of this paper are: eess
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The categories of this paper are: quant-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: funct-an
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The categories of this paper are: acc-phys
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The categories of this paper are: gr-qc
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The categories of this paper are: nlin
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The categories of this paper are: hep-ph