Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Targeting supermassive black hole binaries and gravitational wave
  sources for the pulsar timing array
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin