Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Scientific Life Of John Bahcall   This article follows the scientific life of John Norris Bahcall, including
his tenacious pursuit of the solar neutrino problem, his contributions to our
understanding of galaxies, quasars, and their emissions, and his leadership of
and advocacy for astronomy and astrophysics.

24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph