Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The evolution of radio galaxy emission line regions: Breaking the P-z
  degeneracy   The ionization and kinematic properties of the emission line regions of three
subsamples of 6C and 3CR radio galaxies have been compared. The degeneracy
between redshift and radio power is broken, and the relative importance of
radio power (P), radio size (D) and redshift (z) for the emission line region
properties is determined.

37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org