Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: External Shock Model for the Prompt Phase of Gamma Ray Bursts:
  Implications for GRB Source Models
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
8
The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc