Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The radio properties of the cD galaxy of Abell 2390   We present multi-frequency, multi-epoch radio imaging of the complex radio
source B2151+174 in the core of the cluster, Abell 2390 (z~0.23). From new and
literature data we conclude that the FRII-powerful radio source is the
combination of a compact, core-dominated `medium-symmetric object' (MSO) with a
more extended, steeper spectrum mini-halo. B2151+174 is unusual in a number of
important aspects: i) it is one of the most compact and flat spectrum sources
in a cluster core known; ii) it shows a complex, compact twin-jet structure in
a north-south orientation; iii) the orientation of the jets is 45deg misaligned
with apparent structure (ionization cones and dust disk) of the host galaxy on
larger scales. Since the twin-jet of the MSO has its northern half with an
apparent `twist', it might be that precession of the central supermassive black
hole explains this misalignement.
  B2151+174 may be an example of the early stage (10^3-10^4 yrs duration) of a
`bubble' being blown into the ICM where the plasma has yet to expand.

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The categories of this paper are: hep-th
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The categories of this paper are: mtrl-th
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The categories of this paper are: cond-mat
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The categories of this paper are: q-bio
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The categories of this paper are: nucl-ex
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The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: chao-dyn
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The categories of this paper are: solv-int
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The categories of this paper are: math-ph
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The categories of this paper are: supr-con
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The categories of this paper are: alg-geom
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The categories of this paper are: funct-an
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The categories of this paper are: econ
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The categories of this paper are: comp-gas