Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The SAURON Project - XX. The Spitzer [3.6] - [4.5] colour in early-type
  galaxies: colours, colour gradients and inverted scaling relations
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph