Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Chandra Stacking Constraints on the Contribution of 24 micron Spitzer
  Sources to the Unresolved Cosmic X-ray Background
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
27
The categories of this paper are: comp-gas
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th