Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Simultaneous multi-frequency observation of the unknown redshift blazar
  PG 1553+113 in March-April 2008
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys