Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Is HCG31 undergoing a merger or a fly-by interaction?
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
34
The categories of this paper are: chem-ph