Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unification of 3CR Radio Galaxies and Quasars   We have observed seven powerful FR2 radiogalaxies and seven quasars with the
Spitzer IRS. Both samples are comparable in both, redshift range and isotropic
178 Hz luminosity. Both samples are found to have similar distributions in the
luminosity ratios of Mid-IR high- and low-excitation lines ([NeV]/[NeII]), and
of Mid-IR high-excitation line to radio power ratio ([NeV]/P_178MHz). However,
the MIR/FIR ratio is generally higher for quasars. We further observed Silicate
features at 10 and 18micron in emission. In our sample only quasars show
emission features, while silicate absorption is seen only in the radio
galaxies. These observations are all in agreement with unification schemes that
explain both groups as the same class of objects seen under different
orientation angles.

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The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
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The categories of this paper are: eess
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
34
The categories of this paper are: chem-ph
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The categories of this paper are: quant-ph
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
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The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th