Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: HST, radio and infrared observations of 28 3CR radio galaxies at
  redshift z ~ 1: I. The observations   Hubble Space Telescope images are presented of a sample of 28 3CR radio
galaxies with redshifts in the range 0.6 < z < 1.8, together with maps at
comparable angular resolution of their radio structure, taken using the Very
Large Array. Infrared images of the fields, taken with the United Kingdom
InfraRed Telescope, are also presented. The optical images display a
spectacular range of structures. Many of the galaxies show highly elongated
optical emission aligned along the directions of the radio axes, but this is
not a universal effect; a small number of sources are either symmetrical or
misaligned. Amongst those sources which do show an alignment effect, the
morphology of the optical emission varies greatly, from a single bright
elongated emission region to strings of optical knots stretching from one radio
hotspot to the other. The infrared images display much less complexity.
Although their significantly lower angular resolution would wash out some of
the smaller structures seen in the HST images, it is clear that these galaxies
are less aligned at infrared wavelengths than in the optical. In this paper, we
discuss the galaxies individually, but defer a statistical analysis of the
multi-waveband properties of the complete sample of sources to later papers in
this series.

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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: physics
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The categories of this paper are: supr-con
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The categories of this paper are: hep-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-th
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The categories of this paper are: stat
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The categories of this paper are: solv-int
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The categories of this paper are: chem-ph
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The categories of this paper are: nlin
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The categories of this paper are: patt-sol
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The categories of this paper are: quant-ph
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The categories of this paper are: adap-org
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The categories of this paper are: ao-sci