Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Shaping Proto-Planetary and Young Planetary Nebulae with Collimated Fast
  Winds   Using two-dimensional hydrodynamical simulations, we investigate the
interaction of a collimated fast wind (CFW) interacting with a spherical
asymptotic giant branch (AGB) wind as the mechanism for shaping proto-planetary
nebulae and young planetary nebulae. In particular, we compare our simulations
to the observations of an evolved PPN with multiple, highly collimated lobes,
CRL 618.

37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
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The categories of this paper are: stat
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
2
The categories of this paper are: math