Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The Prevalence of Narrow Optical Fe II Emission Lines in Type 1 Active
  Galactic Nuclei
16
The categories of this paper are: stat
2
The categories of this paper are: math
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th