Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Photometric Monitoring of the Gravitationally Lensed Ultraluminous BAL
  Quasar APM08279+5255   We report on one year of photometric monitoring of the ultraluminous BAL
quasar APM 08279+5255. The temporal sampling reveals that this gravitationally
lensed system has brightened by ~0.2 mag in 100 days. Two potential causes
present themselves; either the variability is intrinsic to the quasar, or it is
the result of microlensing by stars in a foreground system. The data is
consistent with both hypotheses and further monitoring is required before
either case can be conclusively confirmed. We demonstrate, however, that
gravitational microlensing can not play a dominant role in explaining the
phenomenal properties exhibited by APM 08279+5255. The identification of
intrinsic variability, coupled with the simple gravitational lensing
configuration, would suggest that APM 08279+5255 is a potential golden lens
from which the cosmological parameters can be derived and is worthy of a
monitoring program at high spatial resolution.

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The categories of this paper are: alg-geom
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The categories of this paper are: hep-lat
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The categories of this paper are: math-ph
2
The categories of this paper are: math
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The categories of this paper are: eess
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The categories of this paper are: chao-dyn
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The categories of this paper are: cond-mat
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The categories of this paper are: adap-org
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The categories of this paper are: econ
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The categories of this paper are: ao-sci
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The categories of this paper are: plasm-ph
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The categories of this paper are: hep-th
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The categories of this paper are: mtrl-th
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The categories of this paper are: atom-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: bayes-an