Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A quadruply imaged quasar with an optical Einstein ring candidate: 1RXS
  J113155.4-123155   We report the discovery of a new quadruply imaged quasar surrounded by an
optical Einstein ring candidate. Spectra of the different components of 1RXS
J113155.4-123155 reveal a source at z=0.658. Up to now, this object is the
closest known gravitationally lensed quasar. The lensing galaxy is clearly
detected. Its redshift is measured to be z=0.295. Additionally, the total V
magnitude of the system has varied by 0.3 mag between two epochs separated by
33 weeks. The measured relative astrometry of the lensed images is best fitted
with an SIS model plus shear. This modeling suggests very high magnification of
the source (up to 50 for the total magnification) and predicts flux ratios
between the lensed images significantly different from what is actually
observed. This suggests that the lensed images may be affected by a combination
of micro or milli-lensing and dust extinction effects.

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The categories of this paper are: solv-int
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
19
The categories of this paper are: eess
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The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
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The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
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The categories of this paper are: quant-ph
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The categories of this paper are: nlin
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The categories of this paper are: hep-ex
2
The categories of this paper are: math