Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Kinematics of Point-Symmetric Planetary Nebulae: Observational
  Evidence of Precessing Outflows   The discovery of collimated outflows associated to point-symmetric features
in Planetary Nebulae has proliferated in recent years. The systematic variation
of radial velocity that many of them show strongly suggests a uniform rotation
or precession of the ejection direction. Although several physical processes
have been invoked, the formation mechanism of precessing collimated outflows in
PNe is currently an intriguing but unresolved problem.

36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an