Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: AGN and starbursts at high redshift: High resolution EVN radio
  observations of the Hubble Deep Field   We present deep, wide-field European VLBI Network (EVN) 1.6 GHz observations
of the Hubble Deep Field (HDF) region with a resolution of 0.025 arcseconds.
Above the 210 microJy/beam (5sigma) detection level, the EVN clearly detects
two radio sources in a field that encompasses the HDF and part of the Hubble
Flanking Fields (HFF). The sources detected are: VLA J123644+621133 (a z=1.013,
low-luminosity FR-I radio source located within the HDF itself) and VLA
J123642+621331 (a dust enshrouded, optically faint, z=4.424 starburst system).
A third radio source, J123646+621404, is detected at the 4sigma level. The VLBI
detections of all three sources suggest that most of the radio emission of
these particular sources (including the dusty starburst) is generated by an
embedded AGN.

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The categories of this paper are: acc-phys
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The categories of this paper are: funct-an
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The categories of this paper are: supr-con
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The categories of this paper are: ao-sci
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The categories of this paper are: adap-org
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The categories of this paper are: cmp-lg
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The categories of this paper are: cs
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The categories of this paper are: physics
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The categories of this paper are: quant-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: math-ph
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The categories of this paper are: hep-th
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The categories of this paper are: gr-qc
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The categories of this paper are: chem-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: q-fin