Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Discovery of molecular hydrogen in a high-velocity cloud of the Galactic
  halo   We report the discovery of molecular hydrogen absorption in a Galactic
high-velocity cloud (HVC) in the direction of the Large Magellanic Cloud. For
the same HVC we derive an iron abundance which is half of the solar value.
Thus, all evidence points to a Galactic origin for high-velocity cloud complex
in front of the LMC.

26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph