Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Testing the fossil field hypothesis: could strongly magnetised OB stars
  produce all known magnetars?
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci