Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Virial clouds explaining the observed rotational asymmetry in the
  galactic halos   Rotation of galactic objects has been seen in the cosmic microwave background
(CMB) that could be ascribed to molecular hydrogen clouds with, or without,
dust contamination and contamination from other sources. We model the clouds
using the canonical ensemble for pure molecular hydrogen, a mixture of hydrogen
helium and/or dust, in order to constrain the physical parameters of these
clouds. Since the clouds are cold, we justify the use of the canonical ensemble
by explicitly calculating the interaction between the hydrogen molecules and
the CMB photons and determining the time required for thermal equilibrium to be
reached and show that there is enough time for equilibrium to be attained.

34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex