Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the nature of soft Gamma-ray repeaters   Soft gamma-ray repeaters (SGRs) and Anomalous X-ray pulsars (AXPs) are
generally accepted to be magnetars. Recently, Zhang, Xu & Qiao (2000, ApJ, 545,
L127) proposed an alternative viewpoint about the nature of the SGRs (and
AXPs). In this picture, SGR bursts are attributed to the impacts of some
comet-like objects with the central bare strange star. Here I briefly review
this model, and confront it with the detailed observations of SGRs/AXPs. A
comparison to the magnetar model is also presented. Some theoretical issues
concerning the nature of the SGRs (and AXPs) are discussed.

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The categories of this paper are: hep-th
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The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
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The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
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The categories of this paper are: nlin
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The categories of this paper are: math
1
The categories of this paper are: cs
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The categories of this paper are: q-fin
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The categories of this paper are: adap-org