Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On the mass-to-light ratio of the local Galactic disc and the optical
  luminosity of the Galaxy
18
The categories of this paper are: econ
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph