Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Effect of Corotation on the Radial Gradient of Metallicity of Spiral
  Galaxies   The corotation radius in a spiral galaxy is the radius where the spiral
pattern speed has the same velocity of the rotation curve. By compiling results
from the literature for 20 spiral galaxies we verified a strong correlation
between the radius of the minima or inflections of the metallicity distribution
and the corotation radius.

32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex