Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High-Redshift Quasars at the Highest Resolution: VSOP Results   We studied the radio structure of high-redshift (z>3) quasars with VSOP at
1.6 and 5 GHz. These sources are the most distant objects ever observed with
Space VLBI, at rest-frame frequencies up to ~25 GHz. Here we give an account of
the observations and briefly highlight the most interesting cases and results.
These observations allowed us, among other things, to estimate the mass of the
central black holes powering these quasars, to identify large misalignments
between the milli-arcsecond (mas) and sub-mas scale radio structures, and to
detect apparent superluminal motion at sub-mas scale.

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The categories of this paper are: stat
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The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
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The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
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The categories of this paper are: acc-phys
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The categories of this paper are: plasm-ph
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The categories of this paper are: supr-con
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The categories of this paper are: hep-ex
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The categories of this paper are: econ
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The categories of this paper are: alg-geom
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The categories of this paper are: bayes-an
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The categories of this paper are: q-bio
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The categories of this paper are: nlin
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The categories of this paper are: math-ph