Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A new sample of large angular size radio galaxies. III. Statistics and
  evolution of the grown population   We present in this paper a detailed study of a new sample of large angular
size FR I and FR II radio galaxies and compare the properties of the two
classes. As expected, a pure morphology based distinction of FR Is and FR IIs
corresponds to a break in total radio power. The radio cores in FR Is are also
weaker than in FR IIs, although there is not a well defined break power. We
find that asymmetry in the structure of the sample members must be the
consequence of anisotropies in the medium where the lobes expand, with
orientation playing a minor role. Moreover, literature data and our
observations at kiloparsec scales suggest that the large differences between
the structures of FR I and FR II radio galaxies must arise from the poorly
known central kiloparsec region of their host galaxies. We analyze the
sub-sample of giant radio galaxies, and do not find evidence that these large
objects require higher core powers. Our results are consistent with giant radio
galaxies being the older population of normal FR I and FR II objects evolving
in low density environments. Comparing results from our sample with predictions
from the radio luminosity function we find no evidence of a possible FR II to
FR I evolution. Moreover, we conclude that at z~0.1, one out of four FR II
radio sources has a linear size above 500 kpc, thus being in an advanced stage
of evolution (for example, older than ~10 Myr assuming a jet-head velocity of
0.1c). Radio activity seems to be a short-lived process in active galaxies,
although in some cases recurrent: five objects in our sample present signs of
reactivation in their radio structures.

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The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph