Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Very Light Jets II: Bipolar large scale simulations in King atmospheres   Hydrodynamic jets, underdense with respect to their environment by a factor
of up to 10,000, were computed in axisymmetry as well as in 3D. They finally
reached a size of up to 220 jet radii, corresponding to a 100 kpc sized radio
galaxy. The simulations are "bipolar", involving both jets. These are injected
into a King type density profile with small stochastic density variations. The
back-reaction of the cocoons on the beams in the center produces armlength
asymmetries of a few percent, with the longer jets on the side with the higher
average density. Two distinguishable bow shock phases were observed: an inner
elliptical part, and a later cylindrical, cigar-like phase, which is known from
previous simulations. The sideways motion of the inner elliptical bow shock
part is shown to follow the law of motion for spherical blast waves also in the
late phase, where the aspect ratio is high, with good accuracy. X-ray emission
maps are calculated and the two bow shock phases are shown to appear as rings
and elongated or elliptical regions, depending on the viewing angle. Such
structures are observed in the X-ray data of several radio galaxies (e.g. in
Abell 2052 and Hercules A), the best example being Cygnus A. In this case, an
elliptical bow shock is infered from the observations, a jet power of 10^47
erg/s is derived, and the Lorentz factor can be limited to Gamma>10. Based on
the simulation results and the comparison to the observations, the emission
line gas producing the alignment effect in radio galaxies at high redshift is
suggested to be cooled gas entrained over the cocoon boundary.

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The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-th