Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: SOFIA FIFI-LS Observations of Sgr B1: Ionization Structure and Sources
  of Excitation
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th