Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: An X-rays Survey of the Young Stellar Population of the Lynds 1641 and
  Iota Orionis Regions
22
The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg