Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Tentative Size-Luminosity Relation for the Iron Emission-Line Region
  in Quasars   New reverberation mapping measurements of the size of the optical iron
emission-line region in quasars are provided, and a tentative size-luminosity
relation for this component is reported. Combined with lag measurements in
low-luminosity sources, the results imply an emission-region size that is
comparable to and at most twice that of the H$\beta$ line, and is characterized
by a similar luminosity dependence. This suggests that the physics underlying
the formation of the optical iron blends in quasars may be similar to that of
other broad emission lines.

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The categories of this paper are: patt-sol
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The categories of this paper are: hep-lat
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The categories of this paper are: quant-ph
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The categories of this paper are: stat
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The categories of this paper are: hep-ph
2
The categories of this paper are: math
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The categories of this paper are: chao-dyn
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The categories of this paper are: comp-gas
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The categories of this paper are: nucl-ex
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The categories of this paper are: math-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: cond-mat
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The categories of this paper are: atom-ph
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The categories of this paper are: adap-org
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The categories of this paper are: cmp-lg
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The categories of this paper are: ao-sci