Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Water vapor emission reveals a highly obscured, star forming nuclear
  region in the QSO host galaxy APM08279+5255 at z=3.9
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph