Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The 3CR radio galaxies at z = 1: Old stellar populations in central
  cluster galaxies   We investigate the old stellar populations of the 3CR radio galaxies at
redshift z ~ 1, using observations made with the Hubble Space Telescope and the
United Kingdom InfraRed Telescope. At radii r < 35 kpc, the infrared radial
intensity profiles of the galaxies follow de Vaucouleurs' law, whilst at larger
radii the galaxies show an excess of emission similar to that of low redshift
cD galaxies. The locus of the high redshift 3CR galaxies on the Kormendy
relation is investigated: passive evolution of the stellar populations is
required to account for their offset from the relation defined by low redshift
giant ellipticals and brightest cluster galaxies. The 3CR galaxies, on average,
possess larger characteristic radii than the low redshift brightest cluster
galaxies. Coupled with existing evidence, these results are strongly suggestive
that distant 3CR galaxies must be highly evolved systems, even at a redshift of
one, and lie at the centre of moderate to rich (proto-)clusters.

23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math