Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Iron line afterglows: how to produce them   We discuss how a powerful iron line emission can be produced if ~1-5 iron
rich solar masses are concentrated in the close vicinity of the burst.
Recombination, thermal and fluorescent reflection are discussed. We find that
recombination suffers the high Compton temperature of the plasma while the
other two scenarios are not mutually exclusive and could account for the
claimed iron line detected in two afterglows.

31
The categories of this paper are: ao-sci
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The categories of this paper are: q-alg
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The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
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The categories of this paper are: nucl-th
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The categories of this paper are: cs
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The categories of this paper are: eess
16
The categories of this paper are: stat
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The categories of this paper are: hep-lat
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The categories of this paper are: econ